Video Game / Subnautica

Descend into the depths!

"This is the first time I've seen sunlight in months. After all that time in the deep I'd been dreaming of it. Now that I'm back here, I'm finding it hard to enjoy alone..."

— Bart Torgal

Subnautica is an open-world Science Fiction survival game developed by Unknown Worlds Entertainment, creators of the well-received Half-Life mod Natural Selection and its sequel. Having spent almost four years in Steam Early Access and with its V1.0 deadline pushed back five times ^note From September 2016 to January 2017, then to February 2017, then to May 2017, once more to September 2017, and finally to 2018, the game has fully launched on PC as of January 23, 2018, receiving one stable update per month and regular small updates for people who played in experimental mode. The game is available for Microsoft Windows, Xbox One, macOS, PlayStation 4 and Nintendo Switch.

The game is set on an alien ocean world, designated Planet 4546B. The player is the sole survivor of a crashed capital-class ship named the Aurora. The lifepod with which you escaped the Aurora's destruction is equipped with a fabricator, which you must use to cook fish, disinfect water, craft tools, and more. You must explore the underwater landscape of Planet 4546B to find resources and blueprints, build seabases and vehicles, and discover just why the Aurora crashed in the first place while trying to survive the dangers of the deep. All the same, Planet 4546B is filled with strange and beautiful biomes, inhabited by a rich collection of creatures that are no less fascinating than they are dangerous.

It can be described as a Survival Sandbox game: you arrive on the planet with nothing and must explore the environment, gather resources, and supply your fabricator with these resources for Item Crafting. Instead of a procedurally-generated world, this game distinguishes itself with a beautifully-crafted setting that is almost exclusively underwater. This means the player can explore by swimming in any direction, and threats can come from any angle. This also changes the challenges of exploration: instead of wondering "how can I get over there," you will find yourself puzzling "how can I get down there," especially once you recognize that the only way to escape this place requires venturing deeper and deeper into the Eldritch Ocean Abyss.

On the way, you will face various Primal Fears: swimming through Creepy Caves that are dark and twisted enough to get lost in, running Almost Out of Oxygen and nearly drowning, getting dangerously close to hungry Sea Monsters, and more. The game leans heavily on Survival Horror tropes without quite fully crossing the boundary into the genre, which makes for a tense experience with bouts of both terror and wonder. In short, it is a plot-heavy survival crafting game in an Awesome Underwater World with added OMG.

A standalone game titled Subnautica: Below Zero was released to Steam Early Access on the 30th of January 2019, set in an icy region of 4546B. Below Zero was later fully released on May 14, 2021. A proper sequel, titled Subnatica 2, was confirmed to be in production in April 2022, with a planned release year of 2025; the game is made on the Unreal Engine and will include optional co-op multiplayer.

Subnautica: Return of the Ancients tropes are not part of the official canon, and should be placed on its own tropes page for said game mod.

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Subnautica provides examples of the following tropes:

General

• Ability Required to Proceed: Many areas are, if not impossible, at least extremely impractical to access without the right equipment.
  • The first major limitation that the player encounters is their limited oxygen supply and depth limit, which doubles the rate of oxygen consumption beyond a certain depth. This makes extensive underwater exploration very difficult until they've crafted better oxygen tanks and a rebreather to remain in the water for longer periods. Eventually, the player will need to build vehicles that can traverse areas well beyond their ability to dive to conventionally.
  • After the player begins building vehicles, they will have to craft more advanced depth modules for them to prevent the vehicles from being crushed by water pressure in deeper waters (though the player remains fine, beyond the higher usage of oxygen without a rebreather).
  • The crash site of the Aurora in Subnautica is blanketed with radiation leaking from breaches in its reactor shielding, and can only be approached safely if wearing a suit lining rated for radiation resistance; as the area around the ship has the highest density of debris, building the radiation suit is an important step. In addition, certain parts of the ship may require a laser cutter, propulsion/repulsion cannon, and/or a repair tool to enter (sometimes all of the above). Entering the ship allows you to fix the radiation leak, which negates the need for the radiation suit after you've done so and allows you to use better suits and the rebreather in the same area, while a number of the smaller wrecks also require some of these tools to explore them. You're forced to wait until after the Aurora's drive core explodes before you actually get the radiation suit blueprints, though, which does allow you time to prepare for the journey and find the materials needed to craft it beforehand.
  • In Below Zero, the new thermal system requires you to manage your temperature when exposed on land. Certain heat-generating plants, warm caves and sulfur pools all offer respite from the cold. There's also a number of consumables (such as coffee) that restore temperature and cold weather gear that helps retain heat. Conversely, adverse weather on the surface causes heat to dissipate faster.
• Abnormal Ammo: Stock in trade of the Propulsion Cannon, which can lob anything you care to load into its energy field at considerable velocity. With nerves of steel (or an Alien Containment and some patience), it can harness the explosive power of the Crashfish into a formidable weapon.
• Absurdly Sharp Blade: The survival knife, which can cut through solid pieces of coral as if they were butter.
• Acceptable Breaks from Reality: Several, most of which double as Anti-Frustration Features or Artistic License.
  • Decompression sickness is not an issue in this game. Given that the protagonist can only stay underwater for 45 seconds at minimum (more with various oxygen tanks), it would be a little much to require you to wait any decent amount of time whenever you needed to ascend 30 meters. ^note You can toggle on decompression sickness by entering 'nitrogen' through the command console. It is assumed that the hermetically-sealed All-Environment Protection (AEP) Suit compensates for this sudden pressure change, given how it's the first piece of equipment utilized in the event of a starship hull breach.
  • Hatches to get in and out of seabases and alien containments are a single porthole rather than an airlock. Moving around would be greatly hindered if you had to wait each time or, in the case of the alien containment, be blocked off on one side of the room by the extra space needed for the airlock.
  • Diving speed in real life is slowed down by arm movement, but the player uses their arms constantly. This is done to give the player better visual feedback.
  • In real life, vehicle crush depth can't be improved by simply improving the technologies involved; that would require (at minimum) a redesign and strengthening of the hull, and the same goes for additional features like installing torpedo tubes or miniature storage lockers. In-game, all creation devices rearrange matter at the atomic level, and so all installed expansions simply provide their benefits via the same process.
  • Light and colour don't travel very far through the water, with long wavelengths such as red being the first to be cancelled out. For gameplay purposes and a pretty game world, this is ignored.
  • The two moons of the planet should make movement and navigation almost impossible due to their effects on the weather. Instead, the planet (at least in the tropics) has a very calm ocean, and the moons simply form a very pretty sky and major light source at night.
  • While the vehicles have limits, the Player Character is invulnerable to water pressure. The game is unforgiving enough as it is without you being unable to repair or, if need be, Abandon Ship if push comes to shove.
  • Below Zero has an added temperature meter where you need to watch Robin's body heat and restore it on the regular to keep her from succumbing to hypothermia. In practice, the heat gauge works like an "on-land" oxygen meter, and despite being directly below a glacial shelf the water underneath is warm enough, even on the surface, to never have to worry about both Heat and O2 at the same time.
• Action Bomb: The Crashfish, as the PDA puts it, takes a "Mutually Assured Destruction" approach to defending its nest; it'll chase after anything that approaches it and literally blow up in its face.
• Adaptive Ability: The fauna of 4546B is implied to evolve at a much faster rate than on earth. According to the PDA, many of the current lifeforms developed in just the last thousand years, something that would take millions for earth creatures.
• Air-Vent Passageway: Large wrecks are crisscrossed with ducts and tunnels, but by the time you find them they are full of water instead of air. You can enter difficult-to-reach rooms by swimming through them.
• Alien Blood: Originally averted, but now played straight, with the planet's creatures having yellow blood.
• Alien Sky: There are two moons in the sky, one of which is extremely large, resembles Mars, and often causes solar eclipses.
• All Planets Are Earthlike: Although this one has water covering nearly its entire surface, as opposed to a measly 70% of it.
• The Alliance: PDA entries mention the Trans-System Federation, which exists as an authority above the Trans-Govs, of which Alterra is one. According to the Charter, the TSF exists as a military police force dedicated to preventing conflict among its members and guaranteeing relative freedom of movement within its borders. Said Charter is why the Sunbeam is obligated to respond to the distress call from the Aurora, and thus what gets them killed.
  • The TSF is also why the Aurora just so happened to be carrying a dedicated contingent of underwater gear: their secondary mission was to investigate 4546B in search of the Degasi as a favour to the Mongolian Empire.
• Almost Out of Oxygen: There is a high possibility of this occurring while harvesting resources or trying to escape danger.
• Amazing Technicolor Wildlife: The fish in the game are really colorful. Most of the game's flora and all but three species of fauna are bioluminescent.
• An Interior Designer Is You: You can construct your own seabases, decorating the interiors with everything from the crucial (fabricators, lockers) to the frivolous (vending machines, benches). Overlaps with And Your Reward Is Interior Decorating because you need to scan most pieces of furniture before you can build them.
• Anti-Frustration Features:
  • Alien Tablets, unlike practically every other item in the game, give blueprints to fabricate more of them as soon as you pick up their specific colour. In other words, these "keys" to unlock more Architect bases and advance the story are infinitely manufacturable (with relatively uncommon materials) and don't even need to be scanned, so even the most scatter-brained player can avoid being locked out. Convenient if you lose them. Note that, even with thorough exploration, at least one additional tablet must be manufactured to reach the final area of the game.
  • The blueprint for the radiation suit is made available "for your convenience" immediately after the Aurora's remains go nuclear.
  • Unlike vehicles, the Player Character doesn't have a crush depth. You can dive as deep as you want, as long as oxygen lasts, and can exit damaged vehicles for repairs at any time regardless of the depth.
  • In Below Zero, if you die with a beacon in your inventory, it will automatically be deployed with the identifier "Dropped beacon" at the site of your death, allowing you to easily locate and recover any lost items.
  • Unlike most Survival Sandbox games, there is no Stamina Meter, presumably due to how infuriating it would be to drown inches from the surface because your stamina ran out.
• Apocalypse How: A near-Total Extinction on a Planetary scale is clearly evident on Planet 4546B, with later evidence of a Species Extinction on a Galactic scale. The Kharaa Bacterium wiped out about 143 billion individuals on Architect worlds. The settings of the games are notable exceptions with logical justifications:
  • In Subnautica The Sea Dragon Leviathan's attack on the Disease Research Facility in the Lost River released the Kharaa bacterium onto the planet. The volcanic crater in which Subnautica takes place is one of the few locations on the entire planet where any life remains, thanks to the Sea Emperor Leviathan distributing small doses of the enzyme that gives it its immunity through Peepers and the Alien vents.
  • In Below Zero it's implied, though not stated that the reason that life continues in frigid Sector Zero is that the cold slowed or made dormant the bacteria, but the volcanic activity continued to make life otherwise viable. This is evidenced by the leviathan frozen in the glacier with still-viable Kharaa colonies that don't appear to have infected the rest of the wildlife nearby.
• Artistic License – Biology: The Membrain Tree is a composite organism which consists of several types of coral in a symbiotic relationship. The game classifies it as "flora" despite coral being a type of animal.
• Artistic License – Chemistry: The game accurately identifies Real Life elements like titanium or copper by their chemical symbols and minerals like quartz or ruby by their compound. But sometimes, for the sake of gameplay, it breaks the rules of chemistry with a Hand Wave.
  • The "brine" in the Lost River is Grimy Water that's as caustic as acid; merely skirting it while swimming around the area deals considerable damage. Brine in Real Life has no detrimental effects on the human skin no matter the concentration^note unless you marinate yourself in it for multiple hours, which may lead to dehydration. Otherwise, brine baths have been used for medicinal purposes since time immemorial, mostly to treat various skin diseases., much less so if the swimmer is clad in full-body diving gear. However, seeing as the PDS uses Line-of-Sight Name conventions, the name likely isn't indicative of what it actually is - more than likely, it's actually a high concentration of Acid Salt (or similar), which does cause burning.
  • Your fabricator can rearrange materials on the atomic level, but you require a fish for use as a filter membrane (or a specialised filtration machine) to remove salt from water.
  • Polyaniline is a real substance, but gold has nothing to do with its synthesis.
• Artistic License – Engineering: Seabases make some concessions to the needs of an underwater habitat; too much stress on the hull causes it to buckle, and depth directly correlates to the amount of stress exerted. However, for simplicity of gameplay, hull stress is calculated based on the totality of the structure, rather than individual pieces, where each piece has a positive or negative hull value that adjusts the initial value of 10; as long as the value stays above 0, hull integrity is secure. Larger structures like the Moonpool or the observation dome significantly subtract from hull value, but simply slapping some lithium-strengthened reinforcement panels to any other part of the seabase will more than compensate for it.
• Artistic License – Physics: A vehicle one metre above its maximum depth can stay there indefinitely. Drop down to one metre below and it will be crushed and destroyed in seconds.
• Artistic License – Space: The two moons of the planet are in an extremely low orbit judging by their size, and the speed at which they cross the sky. The gravity from Earth's moon causes a daily high and low tide at a much further distance out. Two moons of that size and proximity would cause titanic and unpredictable waves, with fluid forces that would make movement and navigation almost impossible. Aside from mention of a monsoon season, the player never experiences anything other than a calm ocean.
• Attack Its Weak Point: Not a gameplay trait but a programming trait; very large creatures do not have a full-body hitbox and something like the Stasis Rifle won't affect them if they're hit where they don't tangibly exist. This is especially true for the Reaper Leviathan, which despite its size only counts for its head. You can swipe ineffectually at its tail, but you'll only get hit noises and blood fx spawning near its head.
• Audible Gleam: When you pick up gold, diamonds and ion crystals.
• Awesome, but Impractical:
  • The Nuclear Reactor is the most powerful reactor in the game, having both energy output and reserves four times greater than any other form of power generation; a single one can power virtually any activity by itself. It's also the most resource-intensive, requiring significant amounts of uranium and lead for the fuel rods that keep it running, as well as producing spent fuel rods as a byproduct, something no other generator does. If you're willing to build up a large stock of materials, you never need to worry about power, but the other generators either require no upkeep (solar, thermal) or merely a steady supply of fish from an Alien Containment (bioreactor). Subsequent patches significantly upped the total energy value of reactor rods to alleviate this problem, allowing a Nuclear Reactor to run at a full draw for five hours straight before it needs to be refilled, which is roughly eight times longer than a fully-stocked bioreactor.
  • The Cyclops is awesome, but it's also large and unwieldy, which can make it difficult to navigate many of the tight deep sea cave systems it's meant to explore. This isn't helped at all by the multiple Leviathans down there that it can't outrun as it could in open waters, meaning you'll have to be ready to make repairs on the fly while surrounded by scorching temperatures and hostile fauna. Veteran players with intimate knowledge of the cave layouts and entry/exit points may have an easier time, but an upgraded P.R.A.W.N suit is much more versatile when it comes to exploring the game world's deepest reaches. It also isn't easy to keep charged, as it can't be docked at a Moonpool and runs on six Power Cells. The thermal charging upgrade can only be built after reaching the deepest depths, and it doesn't do much good on the surface unless you parked your base near a surface vent. However, they do have some use as a mobile base, particularly one to help deploy the P.R.A.W.N suit at closer distances if you don't already have a base nearby.
  • Tank-grown Crashfish, used as explosive ammo for the propulsion cannon, constitute the most powerful actual weapon in the game. Unfortunately, each Crashfish takes up four tiles (2x2) in your Grid Inventory, so you won't be able to carry more than one or two with you at any given time if you plan on lugging some salvage back home as well. They also need to be manually loaded into the cannon like any other item, which can cost you the second that makes the difference between blowing some predator to smithereens, blowing yourself up as well, or simply being Eaten Alive.
  • The Observatory is the only seabase module that is purely ornamental and thus does not serve any actual purpose beyond stationary sightseeing. Watching the sea around you while safe from harm is certainly cool, but the average player will be much too busy exploring and surviving to do this on a regular basis outside of Creative Mode. This, coupled with the Observatory's disproportionately high impact on hull integrity, makes it something of a luxury addition to well-armoured bases in well-lit areas that are rarely worth its cost. The PDA actually lampshades this in its item description.
  • The Stasis Rifle; whilst it is useful to help escape from more dangerous fauna, it is unlike many of the other handheld tools in that it takes up four inventory slots instead of one. Also a fully charged shot is essential for guaranteed escape from Reaper Leviathans (uncharged shots last merely less than ten seconds), creating the possibility of any leviathan fauna attacking you before the rifle can fully charge. On top of that, only one stasis orb can be shot at a time as firing a shot will replace the already existing stasis orb, making it impossible to freeze more than one hostile fauna if you end up getting cornered. On the plus side, the rifle can fire 20 fully charged shots before a battery change is required.
  • Virtually any form of organic matter can be dumped into the Bioreactor as fuel, but generally speaking, edible fish and certain growable plants are really the only decent option. It's possible to breed huge creatures and use them as fuel, but they take up more inventory spaces and provide less overall power than an equivalent number of edible fish, which are also easier to keep stocked.
• Awesome Underwater World: Virtually all of the planet available to the player is covered in water, with a few islands scattered about, as well as some glaciers in Below Zero. Beneath the sea, most everything is bioluminescent and the ocean is home to an amazing variety of life.
• Bioluminescence Is Cool: During the night and the underwater cave sections, certain fish and plants will have a luminescent glow. This will help you see where you're going. This is especially prominent in the Jellyshroom Caves, Bulb Zone, and Grand Reef in Subnautica, thanks to their massive glowing flora.
• Bizarre Alien Biology: Just about everything.
  • Some of the more extreme examples in Subnautica are the Ampeel with its electro-spikes all over its body, the Gasopod with both its gas mask face and tail-sack, the Reaper with its face clamps, the Sea Treader which uses its snout as its third leg, and the Crabsquid with its... everything.
  • The Architects seem to have had great difficulty wrapping their intellects around parental instincts, presumably a result of being grown from "seed". On top of regularly uploading and downloading from what amounts to a digital format (and incinerating the "analogue" without fuss). Combining this with how Warpers work, the question "How biological are they, even?" crops up, since not understanding the no-holds-barred biological drive behind Mama Bear-mode scuppered them.
  • In Below Zero, meanwhile, you have the Titan Holefish, a near-circular, flat fish with a giant hole in its middle that's large enough for the player to swim through.
• Bizarre Alien Sexes: Everything on the planet is of a single egg-laying sex that can either self-impregnate or mate with any other instance of its species.
• Black Humor: The game has a rather grim sense of humour. Special note goes to the PDA descriptions, which range from poking fun at your current situation to relaying horrific information in a matter-of-fact way. Which ultimately culminates in the Brick Joke / Yank the Dog's Chain that is the first game's The Stinger, as detailed under those entries below.
• Blown Across the Room: The Repulsion Cannon packs an impressive wallop for something so small. It doesn't deal much damage, but the force it applies is sufficient to push even the largest non-Leviathan beasts back several dozen meters. Smaller creatures like Stalkers turn into a Twinkle in the Sky when shot from below in shallow waters, and it can take quite some time before they fall back into the sea. The PDA describes it as a non-lethal weapon, even though realistically such force would cause fatal trauma, while it and the Propulsion Cannon can be used to kill smaller creatures by slamming them into walls.
• Body Horror: The Kharaa bacteria not only affects the immune system, but it also alters the host's DNA and changes their body structure; most notably, it causes green glowing pustules to grow all over an infected individual's body.
• Boring, but Practical:
  • The Seamoth mini-sub is the first true vehicle you'll probably unlock in Subnautica. While it lacks the PRAWN's utility and sturdiness, it's quite fast, reasonably cheap to build and extremely maneuverable even in tight spaces. It also boasts decent storage capacity for something so small, can even be equipped with up to four torpedo launchers, and its upgrades are also quite helpful against anything, including Leviathans. Until the story absolutely forces you to descend to depths below the Seamoth's maximum upgradable crush depth of 900m, the little fellow is generally a much more convenient exploration tool than the huge, unwieldy and expensive Cyclops, or the PRAWN with its serious trouble in getting out of deep-sea trenches without some expensive upgrades. The same can be said for the Seatruck without any modules in Below Zero.
  • Beacons are little gizmos you can drop in the water to mark points of interest - an invaluable asset in a game that lacks a map or any other waypoint system, short of certain mods. They're cheap to build, their blueprint is easy to find, they only take up a single inventory slot, they can even be given individual names to help you keep track of what's what, and you can toggle which ones are visible from anywhere to avoid UI clutter. New players should never leave base without one or two beacons in their pack, especially in the early game stages when you're still discovering new stuff around every corner, but they remain very useful throughout the whole game.
  • The Swim Charge Fins slowly recharge the battery of your currently held tool, but don't grant any increase in speed. However, the recharge rate exceeds the battery drain of the Seaglide, so using them essentially allows infinite use of the Seaglide and makes the speed penalty meaningless.
  • Of all the things you can build in/around your base, perhaps the most useful is the humble growbed. At a mere four titanium, the growbed allows you to grow most kinds of flora at your base without having to travel to their natural habitats, and in greater quantities than you're likely to find in the wild. Home-grown flora doesn't damage you if it would otherwise (acid and deepshrooms) and sometimes produces more resources than a wild plant (creepvines). Hunting down fish for food becomes almost unnecessary when you can grow marblemelons or bulbo trees inside your base and harvest them periodically, and you can even stick one in your Cyclops for food on the go.
• Bothering by the Book: Alterra is apparently quite guilty of this In-Universe, given Captain Avery Quinn's complaints about them in Subnautica. Under the terms of the Trans-Gov charter, ships are obligated to investigate and respond to any distress beacon they come across, with harsh penalties for failing to render aid. Alterra ships have developed a reputation for abusing this to get other people to give them utterly non-essential supplies if they run out.
• Checkpoint Starvation: There are no checkpoints. Each game only has a single manual save slot, while dying warps you back to the last habitat you visited, but that's about it. Be very careful about when, where and under which circumstances you save your game, or you might realize too late that you trapped yourself in a dead end with no way out, not even by reloading. If your computer has a habit of crashing, save every time you unlock a new blueprint or find a rare mineral.
• *Click* Hello: The Crashfish make a sound that sounds a lot like this when popping out of their nests. The chase noise they have can be best described as a gurgling rising in pitch until it goes boom.
• Cloning Body Parts: New organs and the like are a regularity for people who have the money for it in the future world of Subnautica. A guaranteed supply is one of the perks of Alterra higher-ups.
  Paul Torgal: I turned 80 years old last week. I thought I had another 80 in me. But marooned on this planet, there's no swapping out of my liver when the old one fails. Here, I'm mortal.
• Company Town: Downplayed. Some of the info you can download from PDAs highlights the MegaCorp nature of Alterra, which is so big that it effectively constitutes a form of government.
  • At some point in Subnautica, your AI assistant can remind you that everything you collect while stranded planetside belongs to the company by default, with a reminder that you will owe compensation for everything you use to survive. The message then provides an estimate of your running total which is at 3 million credits, and by the end of the game your total will have gone up to a trillion.
  • The sequel story starts with Robin jetting down to the surface of 4546B to look for her sister Sam. One of the log entries she starts out with is a death notification for Sam, that mentions legal services will be calling soon to transfer all open debts that Sam had accumulated to Robin to be paid off.
• Continuing is Painful: When you die on anything but the hardest difficulty (which features Permadeath), you're teleported back to your last habitat or life pod and any items you picked up since then are lost. If you died a death moments after stepping outside your pod, not such a big deal, but it's a different story if you've spent several minutes swimming to and fro and gathering resources. In the worst scenario, you've lost your vehicle during your trip and are warped back to a seabase too deep to reach the surface without aid.
• Convection, Schmonvection: Zig-zagged.
  • There are volcanic vents that have frequent outbursts of hot water and rock fragments. The eruption is damaging and can kill you fairly quickly if you're in it, but otherwise you can get fairy close to the vent before you take any appreciable damage. The edges of the screen will look like they're burning to indicate heat proximity.
  • According to in-game temperature readings, harmless Thermal Vents can reach temperatures of almost 100° C, while volcanic vents and other spots that should seemingly be hotter may be as low as 50° C, with no seeming logic to the discrepancy. Since magma on Earth can be over a thousand degrees (hot enough to boil any water it touches), this is an Acceptable Break from Reality.
  • Whenever you open a damaged bulkhead with the laser cutter, you're cutting through nearly ten inches of reinforced titanium. The hole's edges glow bright orange to red for quite some time, but you'll never take any damage from touching them.
• Crapsaccharine World: Humanity is far advanced, has explored and controls most of the galaxy and can make nearly anything with their extensive replicator-like technology. Yet all of it is controlled and maintained by Mega Corps and humanity basically lives in a strict capitalist/contractual mindset, where even something as simple as a boyfriend/girlfriend relationship requires an extensive contract agreement.
• Crate Expectations: Pretty much anything coming directly or indirectly from Alterra. You need a Propulsion Cannon or Repulsion Cannon to move them out of the way. While some special crates can be manually opened for goodies, most crates can't be opened and are hence rather useless to the player, if intact.
• Cyberpunk: Not too obvious because it doesn't look the part, only becoming apparent if you read all the PDA entries you pick up, but the world of Subnautica is a hellish hyper-capitalistic dystopia. Mankind has developed amazingly advanced technology, yet at the same time, their society has degenerated into an utter nightmare. Charity has officially been declared obsolete in favour of an objectivist mindset, so everyone is on their own and only out for themselves. Megacorps rule their interplanetary domains like nation states without any obligation to treat their employees/citizens like people instead of just assets. Possibly worst of all, even the most private matters like interpersonal relationships and love have been turned into cold business contracts, that can (and are encouraged to) be unilaterally changed or terminated whenever any of the "business partners" feels mildly dissatisfied with the state of affairs, feelings of their partner be damned.
• Damage Is Fire: Your vehicles start sparking and smoking when they're heavily damaged, and the Cyclops actually starts burning from the inside, forcing you to drop everything and put the fires out lest you suffocate. There's even a dedicated fire suppression system you can build and install to make this easier.
• Death Is a Slap on the Wrist: In every mode except hardcore, upon being killed you simply respawn in the last habitat you left, with full health and the entirety of your inventory when you were there last intact. All you lose is what you might have picked up in the meantime. If one's health is low, instead of bothering with health kits a perfectly viable technique is to build a basic habitat tube, a hatch, get in, get out, die intentionally and respawn in the habitat you just created with your health restored. Deconstruct the habitat and go on your merry way.
• Difficult, but Awesome:
  • Thermal Plants. The fragments needed to obtain their blueprints are difficult to find (most abandoned bases are nuclear-powered), they use rare components, and can only be built over high temperature sources, most of which generally aren't near where players would want to build bases. All that said, Thermal Plants have an advantage no other power source does: no upkeep. Once built, they provide a constant stream of energy that doesn't need to be refilled (Bioreactor, Nuclear Reactor), nor does it deactivate periodically like Solar Panels. If placed on a spot with a temperature greater than 60° C, they outperform everything but Nuclear Plants, and you can generally fit several in the same area to take advantage of the hot spot. In addition, the need to build your base near a high-temperature spot can easily be circumvented by building some Power Transmitters to link your thermal plants to your base. Four will match the output of a Nuclear Reactor, and never need to be monitored.
  • Killing a hostile leviathan. A very tricky feat, requiring considerable planning, but once it's dead, it won't come back, making a large section of the map much safer.
• Difficulty Levels: In the order that they appear on the selection screen:
  • Survival Mode: standard difficulty.
  • Freedom Mode: like Survival, but without hunger and thirst.
  • Hardcore Mode: like Survival, but with permadeath.
  • Creative Mode: no hunger, thirst, oxygen or health meters so the player cannot die outside of specific bugged situations^note if they're caught in a Cyclops explosion (PC only; requires console commands to trigger), or stands beneath the elevator on the Neptune Escape Rocket (all platforms). Moreover, vehicles and seabases don't require energy/cannot be damaged, and you don't need materials nor blueprints to craft.
  • Custom Mode:^note exclusive to Below Zero similar to Creative Mode, but you can modify nearly any aspect of the game to your liking. However, you cannot earn Achievements in this mode.
• Double Unlock: At several different levels, no less.
  • Scanning a technology fragment tells you what the technology is and what it does, but only provides a fraction of the blueprint needed to actually build the thing. You have to scan one or two (or, in rare cases, three) additional fragments to actually unlock the blueprint.^note However, if you find an intact piece of technology or, better yet, a data box, you skip straight to the completed blueprint.
  • Once you have the blueprint for a given piece of technology, you have to go to the appropriate fabricator/station/tool and spend the required raw materials to actually construct it.
  • Speaking of "appropriate fabricators"; the fabricators are themselves pieces of technology that have to be unlocked and constructed before they can be used. So, in the worst-case scenario, you have to go through all the above twice: once to get the right fabricator, then a second time to get whatever it was that you actually wanted.
• Early Game Hell: When you first start off, you'll have to swim around with barely any oxygen to spare, hoping to scrounge together enough supplies for basic equipment. As you start unlocking blueprints for vehicles and base equipment, you can begin venturing deeper and worrying less about the basics.
• Eldritch Ocean Abyss: Typically the deeper you go, the more twisted the landscape gets and the more terrifying the fauna become.
  • Subnautica has the Blood Kelp Zone, Deep Grand Reef, Lost River, and Inactive Lava Zone. They all contain some of the most dangerous leviathans in the ocean, and the Lost River is littered with the fossils of ancient, truly titanic sea creatures.
  • Below Zero has the Crystal Caves and Fabricator Cavern, the two deepest biomes in the game and home to the dangerous Shadow Leviathan and some truly surreal terrain.
• Enemy Scan: One of the core tools is a scanner to scan just about everything, hostile fauna and flora included, along with yourself. The results of each completed scan are stored in the PDA, which therefore in part serves as a Monster Compendium.
• Enemy Mine:
  • Different species of predators are just as likely to territorially attack each other as they are to attack you. This is especially visible in the second Degasi seabase, where Warpers and Crabsquids will fight over the exclusive right to harass you while you're exploring it.
  • Holding Peepers or other small prey fish in your quick slots will let Stalkers eat them, and they won't attack you, for a while. They even occasionally bring piles of scrap.
  • It seems to work for Reaper Leviathans as well, but don't count on it saving your ass. There's an animation where the player raises their arms, and the screen goes black, but there's no You Died message...
• Equipment Upgrade: There's a modification station, a vehicle modification station, and two specialized fabricators to improve your stuff.
• Everything Is An I Pod In The Future: All Alterra equipment is shiny white, with smooth surfaces, rounded edges and corners. Any larger sea base you build will inevitably look like an Apple designer's wet dream.
• Everything Sensor: One of the available rooms for your base is the Scanner Room. It is able to detect virtually any resource within a certain range and highlight it, from mundane materials like limestone deposits to scannable fragments and sunken wrecks. It can be upgraded for better range and scanning speed, and a HUD chip can be built to pipe the data directly to your helmet, making it an invaluable tool for gathering lots of mundane resources quickly. Below Zero adds a handheld version with much shorter range, but is still helpful when far from your base.
• Everything Trying to Kill You: Averted, particularly in the Safe Shallows: there are lots of passive fish which will never harm you at all, and also plenty of defensive fish who will only attack if you get too close or bother them. The truly aggressive species are actually a minority, but they're still plenty omnipresent and extremely dangerous, seeing how even a single one of the biggest species can often kill you in a flash.
• Falling Damage: It does exist in the game, though you don't need to worry about it much since Subnautica is mostly set underwater. Just be careful while exploring the Aurora or the islands.
• Family-Friendly Firearms: Lethal firearms are forbidden from being created by the fabricator, mentioned to because of a massacre on Obraxis Prime. You can arm some of your submersibles with torpedoes, but the only true handheld weapon is the non-lethal stasis rifle.^note There is also the survival knife and the propulsion/repulsion cannons, but these are more tools than weapons.
  • The only true firearm is an alien rifle, albeit suspended in an impenetrable display case within the Quarantine Enforcement Platform.
• Fastball Special: Any creature caught and flung by the Propulsion cannon. Pair it with tank-grown Crashfish for explosive results.
• Final Death Mode: Hardcore mode. Exactly like Survival mode, except you only have one life and have no oxygen warnings. Forget to check your meters at your own peril.
• First-Person Snapshooter: Optional. Pictures taken can be used as decoration in one's base by means of the Picture Frame.
• Fluffy Tamer: The secondary function of the Alien Containment module, as any predator you hatch inside it will be docile towards you. This continues to apply if you release them from the tank and they become full-grown. Ever wanted a pet Ampeel, Crabsquid or Boneshark? Now's your chance.
• Gentle Giant:
  • Some of the creatures you encounter will be this, such as the monstrous, loud, but harmless Reefback. You won't know unless you approach them, though.
  • The Titan Holefish has gotten so reliant on the small fish it shares a symbiotic relationship with for food and defense, that it's in a perpetual state of calm and seems to be barely aware of its surroundings.
• Gigantic Adults, Tiny Babies: The larger animals emerge from their eggs in the Alien Containment tank no bigger than a peeper, making even the likes of Crabsquids or Cryptosuchus look cute.
• Glowing Flora: Many deep-sea plants (including trees) are just as luminous as the rest of the living things there. This was probably to emphasize the abyssal aesthetic since many bioluminescent creatures inhabit this biome in Real Life, and because Bioluminescence Is Cool.
• Gratuitous Laboratory Flasks: Several wrecks are strewn with nonfunctional lab equipment including microscopes, analyzers, and glass flasks. They are useless to you, but you can invoke this trope by taking them back to your base and placing them decoratively. In one case, you can even find a forklift.
• Gravity Screw:
  • The whole point of the Propulsion Cannon, a tool meant for picking up and moving/throwing small to medium-sized objects. Seeing how the thing is a barely disguised Expy of Half-Life 2's Gravity Gun down to a very similar look, this shouldn't come as a surprise.
  • The Quarantine Enforcement Platform has a vertical anti-gravity lift to facilitate movement between the ground floor and the level a hundred meters below.
• Grid Inventory: Some items take up more than one space in your inventory.
• Guide Dang It!:
  • Part of what makes Subnautica's survival atmosphere so intense is that you're told next to nothing upon starting a new game, and things barely improve from there on. There are no instructions, no tutorial, not even a map outside of mods, least of all something like a quest log (or even quests to begin with). The only real HUD markers you get are from the few other Aurora survivors, and that ends fairly quickly. Afterwards, you're completely on your own, and unless you consult a guide, you can spend hours upon hours getting lost in subterranean tunnel systems, wondering if there's even a point in risking your life down there and if there is, what you're supposed to accomplish in this place. It does make for an epic adventure full of astounding discoveries though.
  • Any blueprints you learn will list the ingredients you need to create the item. However, if one or more of those ingredients also require a blueprint — for example, aerogel — that you haven't learned, the game won't tell you how to make them until you've found the necessary components.
  • Once the Aurora's drive core explodes, the area around it is flooded with radiation and requires a Radiation Suit to withstand. If a player decides to put off repairing the reactor for long periods, the radiation 'bubble' will gradually expand in size, making more of the surrounding area - up to a max range just short of Lifepod 5 - unfit to explore without the Radiation Suit.
• Heal Thyself: Medical packs heal you by 50 points instantaneously.
• Hollywood Drowning: Zig-Zagged. Running out of oxygen underwater is deathly quiet: all sound fades, your vision dims to black, and you die seconds later. If you manage to reach air just before you expire, your Player Character will gasp and sputter back to life.
• Highly Visible Landmark: Downplayed in that most navigation in the game is done underwater (with the low visibility that implies), but whenever you surface you can see the gigantic, burning wreck of the Aurora from just about anywhere in the playable area. Until you get a proper compass and enough beacons, you can guide yourself by whether you're closer to the stern or the prow, and how much closer or further away it is.
• Hot Blade: The sole upgrade for the Survival Knife equips it with a heating element, causing the edges of the blade to glow red. This doubles its damage output (but makes it useless against heat-resistant wildlife), and it both kills and cook edible wildlife in one strike.
• Idiosyncratic Mecha Storage: Exiting your P.R.A.W.N. Suit while on land will cause it to automatically crouch down so that you can reach its top-mounted access points.
• In-Universe Game Clock: There's a day-night cycle that not only informs what creatures you'll see but also how aggressive they'll act; most are bolder at night. Story progression is also partially determined by the passage of time. Case in point: the Aurora's reactor goes critical after seven days have passed, at which point you will be given the blueprints for the Radiation Suit, which you need in order to get close enough to the Aurora to loot the wreckage for the parts needed to unlock equipment needed to progress further.
• In-Vehicle Invulnerability: Zig-zagged. You can't be hurt (except by hunger or thirst) when you're inside any vehicle or base. While head-on collisions might damage your vehicle, you'll never be knocked unconscious by flying shrapnel like in the opening cinematic. However, the Warpers have the ability to teleport you out of your vehicle so they can attack you.
• Item Crafting: You start this Survival Sandbox game with nothing. You will need tools, supplies, and vehicles; you have to fabricate them all yourself.
• Item-Drop Mechanic: Completely Averted (contrary to genre conventions). You can catch small fish to eat, but other than this you gain no resources from killing wildlife, and you have few weapons anyway. Tame creatures can be used as fuel, but hunting is not rewarded.
• Item Farming: Before you do any Item Crafting, your fabricator must be supplied with the appropriate raw ingredients. Fortunately, you can find these in the ocean surrounding you, and certain materials are common to certain areas. You'll thus find yourself revisiting the same spots on a fairly regular basis to resupply.
  • Titanium and quartz are among the most common ingredients, forming the basis for structures and vehicles.
  • The primary function of the Alien Containment is to breed fauna, which makes farming food, water and energy a breeze, freeing up time to truly begin your exploration of the ocean.
  • Growbeds and plant pots allow you to grow flora at your home base without having to risk a trip to the relevant biomes. This is especially useful for underwater flora like gel sacks, which are required components for more complex items.
  • Some players have devised a trick for farming Stalker Teeth: approach Stalker territory and drop a handful of scrap metal pieces in the outer area. The closest Stalker will soon proceed to swim back and forth between the pieces, mostly ignoring the player while losing teeth regularly.
• Jump Jet Pack: Built-in feature of the PRAWN Suit. This Mini-Mecha does not float, so when you pilot it you Walk, Don't Swim. Jets let you jump off the seafloor and propel yourself upward for a limited time, providing some vertical mobility, while an upgrade will improve the jump. It is only designed for relatively low-gravity or high-pressure environments, making it effective underwater but still not very useful on land. In Below Zero, the PRAWN Suit's jets can also propel you forward.
• Kaiju: The infamous Leviathan-class lifeforms are gigantic, measuring between 55m (Reaper) and 200m (Sea Emperor) in length. It's probably not a coincidence that some of them bear more than a few similarities to the villainous monsters in Pacific Rim. Their database entries also lampshade that these monsters are rapidly approaching the size limit for sustainable organic lifeforms... which is immediately turned on its head when you find the aptly named Gargantuan Fossil, the remains of an ancient super predator that died roughly three million years ago before it came to rest in the Lost River Bone Fields. Its skull alone is almost 100 meters long (large enough to swallow the Cyclops whole), its canines measure 10-12m, and the whole creature is estimated to have exceeded 1,200m in length back when it was alive. Kind of makes Reapers, Ghosts and Sea Dragons look cuddly when you realize this thing ate those for breakfast.
• Killed Off for Real: If you manage to actually kill a Leviathan-class creature, it will thankfully stay dead and never respawn.
• Kraken and Leviathan:
  • The PDA uses the term "Leviathan Class" to describe the biggest biologically feasible fauna. Note that this is just a size classification, as the Reefbacks and Sea Treaders are considered Leviathan Class. On the other hand, if a species includes the word "Leviathan" in their actual name (e.g. Reaper Leviathan, Ghost Leviathan), it's probably best to run and don't look back.
  • One PDA entry indicates that the tremendous size of the Sea Emperor means it has to recalibrate the size category.
  • In the Lost River biome, players can come across a few multi-million-year-old skeletons. One, in particular, has jaws large enough to comfortably fit the Cyclops inside.
• Laser Cutter: The Aurora wreckage has many doors that are partially crushed and inoperable. This tool allows you to cut a hole through them and gain access.
  • In Below Zero, it has more uses: it can cut holes in the ice and open sealed supply crates.
• Late to the Tragedy: There are plenty of distress calls indicating other people survived planetfall, but they are all missing and presumed dead by the time you get there. Many of them have large holes in their life pods as if a big creature chewed its way in. You never see a single dead body in the game, but your PDA indicates that the local Cave Crawlers have some human DNA in their digestive tracts.
• Loading Screen: There's only one when you're starting a new game or loading a saved game.
• Loads and Loads of Loading: Downplayed. Unless you have a fast computer/hard drive, you'll typically be staring at that initial loading screen for several minutes.^note Even on a mid-range SATA 3 SSD drive the game can take almost a whole minute to load. Having a budget traditional laptop hard drive (whose speed clocks in at 5400rpm) would probably afford you enough time to go raid the refrigerator for a quick snack while the game is loading. While the game was still in development, the loading time will actually increase the more you interacted with the world due to the way the save games worked. Apparently, this was fixed in the final release. The game switches to dynamic loading after that, and you'll never see a loading screen ever again once unless you quit back to the title screen.
• Made of Iron: Most hostile fauna counts, as it's extremely difficult to outright kill anything larger than a cat. Even the PRAWN Suit's giant drill arm will merely chase off attacking predators like Bone Sharks for a short while; you can drill into one for a full minute or more without the beast dying, and that's next to impossible to pull off anyway without glitches, because all predators are much faster than the PRAWN. You need to get really creative and/or persistent if you want something dead.
• Magic Tool: The Repair Tool is handheld and can be used to repair almost any device in seconds.
  Most people don't care why it works, just that it saved their life that one time — but in case you're curious, it combines scanner and fabricator technologies to determine the proper specifications for the targeted object, and then rearranges the available physical material to match the original specs.
  • Building Is Welding: Early designs had a welder that could be used to repair things, which was later changed to the repair tool. It still looks and sounds like a welding torch and produces a spark at the end when activated.
• Master Console: It is one of the few games to have console commands on the console versions. ^Details L1+R1+X on PlayStation 4, LB+RB+A on Xbox One to open the console. See here for a full list of commands. Enjoy!
• Meaningful Name: Invoked, since your PDA is generating names for creatures as you encounter them, so almost all of them have names directly tied to their distinctive traits. In fact, the Reginald actually sticks out as being the only fauna that doesn't have such a name.
• MegaCorp: The 37 "trans-gov" corporations that control the galaxy. Two matter in the game: The Alterra Corporation, which owns the Aurora and makes just about every piece of human technology seen, and the Mongolian Empire, which owns the Degasi. A "trans-gov" is legally defined in-universe as any entity, corporate or state, that claims ownership of at least one planet and one phase gate under the terms of The Charter. There are a few actual governments in their ranks, but most are implied to be full-blown Mega Corps.
• Mêlée à Trois: Different species of hostile creatures tend to dislike each other just as much as the player, and will often fight if they happen to be in the same vicinity. In particular, many creatures will automatically attack any Warpers that happen to enter their territory.
• Mellow Mantas: There are several ray-like creatures native to 4546B — Rabbit Rays, Jellyrays, Ghostrays, Crimson Rays, and even the flying Skyrays. They're all poisonous enough to be inedible, but they're also peaceful herbivores. Jellyrays and Ghostrays are particularly serene-looking, being highly bioluminescent. Below Zero introduces another couple species, Arrow Rays and Arctic Rays, but those are less mellow — Arctic Rays are carnivorous (though they only eat small fish and won't go after anything human-sized), and while Arrow Rays are actually edible, they'll attempt to fight back against anything trying to eat them.
• Mini-Mecha: The Pressure Re-Active Waterproof Nanosuit A.K.A. the PRAWN Suit, previously the Exosuit. It shares some upgrades with the Seamoth such as Pressure and Impact Compensation, but also has special arm variants that can be interchanged separately from the regular upgrades.
• Mix-and-Match Critter:
  • Some of the creatures have elements of two or more creatures. The Crabsquid is an octopus with Japanese Spider Crab legs and claws. The Sea Dragon Leviathan is a crocodilian with squid tentacles for its lower half, and the Emperor Leviathan is similar but with an insectoid/crustacean head.
  • In-Universe, the Warpers are artificial creatures whose bodies are composed of organs and tissues from dozens of different species, most of them being alien to 4546B. Below Zero shows this to be true of the bodies used by the Architects themselves as well, as parts from 27 unique creatures are identified in said bodies.
• More Predators Than Prey: The dev team worked hard to avert this one: sure, there are some big, scary fish in the sea, but there are also lots of little, less scary fish that the bigger ones will prey upon instead of you, at least some of the time.
• Nature Is Not Nice: Most of the predators don't deliberately seek you out; you just happen to be snack-sized and in the vicinity. They'll just as happily eat small fish. Likewise, the greatest threat in survival mode isn't necessarily the wildlife itself; it's running out of food and water, or running out of oxygen while looking for resources.
• No Biochemical Barriers: You're on an alien planet, but it just so happens to have a nitrogen-oxygen atmosphere and liquid water. Most of the sea life is edible, and those that aren't are specifically stated to be poisonous in order to avoid being eaten by larger species, rather than just being incompatible with a human digestive system. Of course, this is somewhat necessary for the game to be enjoyable to play.
• Notice This:
  • Important stuff like databoxes and PDAs glow brightly in the dark, which makes them easy to spot even from long distances. It also makes it advisable to switch off your flashlight at least once per room while you're exploring wrecks so you don't miss them because your light overpowered theirs.
  • Scannable fragments that unlock new blueprints tend to be a bit less obvious, but they do stick out from among the worthless rubble once you know what to look out for, and they also trigger a small scanner icon in the lower right corner of the screen when you enter their rough vicinity, to alert you to their presence (helpful in wrecks because the fragments often blend in very well with the walls and floors).
• Not the Intended Use:
  • The Picture Frame is meant for pictures taken in-game. However, since those pictures are stored in a folder, it is possible to take any image that you want, place it in the folder, and then have the game treat it as another in-game picture. This can be used for an extra level of base customization, but the most popular use is to upload a user-made map because the game has no mapping system of its own unless you use certain mods.
  • Normally, you're expected to create Batteries via its blueprint, but most/all tools are automatically provided with a free battery upon creation. Therefore, if one is missing a spare in a Seabase and don't have the necessary materials to make one, they can simply make another tool, take the free Battery out of it, then deconstruct the tool to retrieve the spent materials.
• Numbered Homeworld: The planet is never given any name but 4546B.
• Ocean Punk: It is a mostly-underwater survival game.
• One-Gender Race: The PDA mentions that all life on Planet 4546B is only one sex. They do not reproduce asexually though as each individual can both carry and fertilize eggs.
• Oxygenated Underwater Bubbles: Either naturally when produced by Purple Brain Coral or manmade when produced by a pipe system.
• Oxygen Meter: Unaided, you can hold your breath for 45 seconds, and going below 100 meters without a Rebreather cuts that time in half. You can get tanks that will add to your air, but you can still run out if you're outside of a powered vehicle or station (and if those lose power, they'll soon lose air too). Running out won't immediately kill you, though; you'll begin to black out when your meter runs down, and if you manage to get a gulp of air before completely losing consciousness, it'll revive you.
• Patchwork Map: Complete with Law of Cartographical Elegance.
• Permanently Missable Content: Several PDA entries, particularly those related to plot-critical events especially those involving the infection's progress through the protagonist and the clues to finding certain alien locations downloaded from the QEP, become unavailable once you progress/skip past them and/or ignore the cues to scan yourself. This can be particularly frustrating for those looking to collect every PDA entry in one playthrough.
  • This can also be an issue for those looking to scan all the species in the game. A bug sometimes causes Bladderfish to stop spawning in the Safe Shallows, and through simple attrition their numbers will eventually whittle away to nothing, preventing players from ever scanning them if they failed to do so at the start of the game.
• Primal Fear: So many, and so intense. While not primarily a Survival Horror game, it's sometimes just as frightening.
  • Thalassophobia is the fear of the ocean — and what might be lurking beneath it. It can be bad enough here on Earth, but on an uncharted alien planet, where nothing is familiar and you know (with certainty) that Leviathan-Class Sea Monsters swim in the Eldritch Ocean Abyss, it's worse. If you don't see or hear them, it only means they are hidden... for now. You are utterly out of your depth and in over your head. (Pun intended.)
  • Running Almost Out of Oxygen deep underwater. And, if you fail to make it to the surface in time, death by drowning.
  • Finding some items requires you to enter and navigate Creepy Caves underwater. Add Claustrophobia to the already-ample terror.
  • Being completely alone.
• Procedural Generation: Unconventionally for a Survival Sandbox, Averted. The map is the same in every playthrough, but your starting position may be different.
• Product Placement: The Cyclops is modeled after the class of submersible from the private deep sea exploration firm OceanGate; the company received a special thanks in the credits as a result.
• Pure Energy: Any exterior power source (and power transmitters) transmit the energy to the nearest base not by cables, but by a beam of sorts.
• Ramming Always Works: If you've got a Repair Tool on hand, it's reasonably effective to use the Seamoth, and especially the tougher Seatruck in Below Zero, as a battering ram to bludgeon small-to-medium size enemies to death. Don't try this on hostile leviathans, however.
• Regenerating Health: Your health recovers slowly but surely, and is most reliable when your hunger meter is above 100.
• Respawning Enemies: The creatures of Planet 4546B eventually respawn. As of the full release, however, medium to large creatures no longer respawn, meaning it is possible to kill them all, including most Leviathans.
• Ridiculously Fast Construction: Alterra's fabricator technology can construct virtually anything in a matter of seconds, assuming the user provides the blueprints and the required materials. It can even build the Neptune, a huge single-stage interorbital rocket, in less than three minutes.
• Robo Speak: Averted by the AIs that manage your bases and vehicles, but played straight by the escape pods' automated distress signal transponders.
• Rule of Scary: In both games, the largest predators (Sea Dragon Leviathans in the first and Shadow Leviathans in the second) will only be found patrolling the large deep-sea caves that are the final areas. It really doesn't make sense that such enormous creatures would live in such relatively barren parts of the sea when they should be up above where there's more food, but it wouldn't be a final area without big scary monsters.
• Salt Solution:
  • Salt is needed to preserve dead fish or they'll go bad very quickly. It is also used as an ingredient to create bleach for disinfecting water, and it's needed for a number of vehicle upgrades.
  • Salt can also prove hazardous to your health. The brine rivers and lakes in the Lost River biome are so highly concentrated that touching them without a PRAWN Suit is akin to getting doused in acid, dealing high damage in very short ticks.
• Scenery Porn: The game's main selling point — the world is gorgeous. The designers worked very meticulously to invoke this trope, and the result truly must be seen to be believed.
• Sea Monster: Plenty of them fulfil the classic tropes — giant squids, Krakens, and Leviathans galore, in addition to exotic but "normal-sized" sharks. The Crater's Edge (formerly known as the Void) surrounding the play zone used to host an onslaught of dangerous fauna to discourage players from venturing too far without resorting to an Invisible Wall or Wrap Around, but as of the full release the game jumps directly to spawning adult Ghost Leviathans to chase the player until they escape the area and cause them to despawn.
• Series Mascot: The Peeper and Reaper Leviathan are the most prominently featured in marketing materials.
• Shared Universe: With Natural Selection 2, also made by Unknown Worlds. Originally the name of the Alterra corporation on the Knife's blade was considered merely an easter egg, until a log file coded with a Caesar cipher and ASCII on the Habitat Update’s promotional webpage mentions “the Kharaa conflict," and as the game's wiki notes, the Kharaa are, in fact, connected with the Kharaa Bacterium in some fashion. ^note The current line is that the Kharaa in each game are simply different manifestations of the same bacterial life form, owing to the radically different environments in which they're found and possibly due to the Architects meddling with the strain found on 4546B.
• Shown Their Work: Before lead became a resource to find as any other (Machinery update), it was manufactured by combining copper and silver ores. This reflects the fact that lead can be found in ores of other metals, such as Galena (an ore of silver).
• Single-Biome Planet: 4546B is officially classified as a "Category 3 Ocean Planet", seemingly playing this trope straight. However, the underwater world has rich and diverse areas, varying not only by location but also by depth. There are also two tropical islands on the map, plus the arctic biome that is the setting of Below Zero.
• Sinister Geometry: It's debatable how evil the Architects really are, but their buildings sure look plenty sinister, looking like some architectural collaboration between the Forerunners and the Borg. Everything's assembled from cubes of various sizes, the material is some black, nearly indestructible alloy covered in green Tron Lines, and the architecture itself is oppressive, monolithic and strangely reminiscent of temples/shrines even though the facilities the player visits are exclusively scientific, military or industrial in nature.
• Soft Water: Played straight; you can jump into the ocean from any height without fear of injury. Just be careful not to hit anything solid on the way down — the game does have Falling Damage on dry land.
• Sound-Coded for Your Convenience: All the wildlife is quite noisy, and makes unique sounds to boot. Learning which creatures make which sounds lets you know when it's just a big Reefback saying hi and when you're about to be Eaten Alive.
• Space Isolation Horror: The game leaves you stranded on an ocean planet full of large, terrifying sea monsters who want to eat you.
• Sprint Shoes: The basic underwater variant are a pair of silicone flippers, which slightly increase the player character's baseline swimming speed and can be upgraded into Ultra Glide Fins. The straighter variant though is the Seaglide, which is a fancy DPV, or a propeller with handles. It comes with a holographic topography map and flashlight, but drains its battery fairly quickly if those features are used. Paired with the Swim Charge Fins, it can be kept charged indefinitely as long as the map and flashlight are switched off.
• Stat Death: Running out of oxygen won't do anything to your health bar, but you'll die anyway if you don't reach an oxygen-rich environment soon.
• Strong Enemies, Low Rewards: It is possible to kill large creatures (including Leviathans). However you have almost no offensive weapons, so slaying one is difficult and tedious. And since there is no Item-Drop Mechanic, you get no reward for doing it.
• Sufficiently Advanced Aliens: Implied. While humans are advanced enough to have trivialized manufacturing and engineering thanks to employing direct matter manipulation and have encompassed most of the galaxy, the technology of the Architects remains inscrutable enough that only the most obvious interfaces can be interacted with — the base materials used in construction are completely impervious to all available tools and have not yet been classified by human science, and the nature of their computer storage and energy manipulation systems remains completely unknown.
• Super-Persistent Predator: Largely averted. Most predators will tend to avoid the player character unless an opportunity presents itself, and even then will tend to give up the chase if the player character can outrun them or proves themselves capable of hurting the predator; a good knife wound will often send the predator swimming away as fast as its fins can propel it. On the whole, they tend to prefer easy prey. The closest thing that comes to playing this straight is the Reaper Leviathans, which seem to be apex predators. If one has spotted you, run and don't look back.
  • That said, the Seamoth Perimeter Defense system allows you a quick zap to minimize hull damage that will send Reapers the other way, or a longer charged-up one that can outright kill smaller predators (including bone sharks). Reaper, Ghost and Sea Dragon Leviathans won't be discouraged for long by the shock, but you'll need every second to have a chance.
  • They also won't be distracted for long by Creature Decoys which can be hand dropped or launched by the Cyclops. Hell, even being scooped up in a PRAWN suit and using the drill arm(s) to fight back won't make a Reaper let go of you, to say nothing of the other two mean beasties.
  • Though a risky venture, Reaper Leviathans will gladly take any fish you have on hand and leave you alone for a short while, giving you enough time to escape.
  • The single most reliable way to evade them is the judicious application of a Stasis rifle or a Vortex torpedo, which are capable of paralyzing a Leviathan for several precious seconds while you try to flee.
• Surveillance Drone: The Camera Drones, which are created when you build a scanner room in the original game, but must be crafted separately in Below Zero, can be controlled by the player from a scanner room and used to scout out the surrounding area.
  • Below Zero also adds the Spy Pengling, which can also be used to access small tunnels, collect fur tufts from Snowstalkers, and take selfies.
• Unexpectedly Realistic Gameplay:
  • It's not obvious from the start that oxygen tanks actually store oxygen seperately, rather than merely increasing your cap. If you have several in your inventory, each has its own supply and can be swapped out as the equipped one depletes. Similarly, each individual tank must be refilled with air by equipping them.
  • Also applies to the game as a whole. The vast majority of contemporary survival games have tutorials, quests, map markers (not to mention a map in the first place), a more or less strict narrative with a clear ultimate goal, and so on. Subnautica's total lack of any hand-holding can be baffling to new players until they switch their standard video-gaming expectations back to IRL behavior in uncharted territory: survive the first day, come up with a plan to get the hell out of there, and then survive long enough to figure out how to do just that.
• Survival Sandbox: Much of the gameplay is about surviving and exploring the world.
• Under the Sea: Almost the entire game takes place in the ocean, with a couple of islands and the non-submerged half of the Aurora being the only exceptions.
• Underwater Base: You can make these using the Habitat Builder and raw materials such as titanium and glass. The dome aesthetic is present in the design of the Multipurpose Room as well as other structures, with tubes connecting them together. Building them is necessary for more advanced crafting and general item storage.
• Unintentionally Unwinnable: There are a number of ways to get yourself stuck in the deep sea with no way to continue the game, exacerbated by there only being one single save-game per campaign and no autosaves.
  • If you die and aren't playing on Hardcore, you're warped back to the last habitat you visited. If that death also involved the destruction of your vehicle, and your last habitat happens to be situated too deep to reach the surface by swimming and you don't have any resources close enough to build a new vehicle (or a habitat builder to deconstruct your habitat and reset your spawn point to the original life pod), you're stuck there.
  • It's quite easy to underestimate the time it can take to navigate the game's labyrinthine tunnel systems. Fail to pack enough spare power cells for your vehicle, or enough batteries for your repair tool, and you can find yourself in the same situation as above very suddenly. The loss of your vehicle at great depths in general is an almost certain death sentence even if you initially survived its destruction.
  • You may also simply die of thirst or starvation on such excursions. The latter can usually be staved off by catching some edible fish, but if you don't have the Thermoblade (which cooks any small edible fish on contact), eating them raw seriously lowers your hydration. Always make sure you have a healthy supply of food and especially water before you head out.
• Unstable Equilibrium: The beginning of the game is almost exclusively about basic survival: getting food and water to stay alive long enough to get equipment to survive the planet's dangers. Obtaining the means to farm your food is a huge step in freeing up time to spend on exploration, but certainly isn't the only boost forward.
• Video Game Cruelty Potential:
  • The Bioreactor breaks down any organic matter as fuel. Including innocent creatures and their eggs, if you wish.
  • It's one thing to hit/shock an attacking predator in self-defense, it's another to do so when a creature is just minding its own business, especially the ones who are completely peaceful. You can cruise around in your Seamoth shocking any and all creatures that get close, including your loyal pet Cuddlefish.
• Well-Intentioned Extremist: The Architects. They were the ones responsible for shooting down the Aurora and Degasi, and later the Sunbeam that lands to try and rescue you in front of your own eyes. However, there's a reason they're doing all of this. A bacterial epidemic ravages the planet, which has infected enough creatures to become the norm. The Architects are simply trying to keep the bacterium from infecting anybody else. They also created the Warpers.
• Worthless Yellow Rocks: Played with. Once you know where to look, it is not hard to find plenty of "precious" metals and minerals like silver, gold, and ruby. Since there is nobody to trade with, their only value is their utility in fabricating electronics.

Subnautica

• Abandoned Area: The various abandoned Degasi seabases. The Sparse Reef also invokes this when the PDA questions why it barely features any life.
• Action Prologue: The game opens with the Player Character strapping into a lifepod to a cacophony of alarms, with no knowledge of what's going on except that it's time to Abandon Ship. Once you've made planetfall and put out the fires in the pod, you can finally take a breather and start planning your objectives.
• Ascended Fanboy: Let's Play channel Neebs Gaming made a series of videos essentially roleplaying through the game during development. They were contacted by the developers and ended up providing some voice acting for the finished game as part of Alterra HQ (which actually serves as a Brick Joke for the roleplay in question, which near the end features a scene with Neebs' character offering a job with Alterra to Apsero's character).
• Adventure-Friendly World: A couple of common survival blueprints are not available to the protagonist because their PDA files have become corrupted. Fragments or examples of the items need to be found and scanned before they become available for construction.
• All Flyers Are Birds: Zig-zagged; the only flying creature you see, the Skyray, looks for all intents and purposes like a flying manta ray, but the scanner says that its "fins" are actually composed of oddly-shaped feathers.
• All There in the Manual:
  • Thanks to your tight-lipped protagonist and a fairly limited number of radio messages received from other survivors and the occasional Warper squad, piecing together the game's plot from audio and events alone is next to impossible. If you want to learn the whole story, you'll have to spend some time digging through the exhaustive in-game database, with particular emphasis on anything concerning the Architects (or "aliens", as the PDA designates them) and the Kharaa bacterium.
  • The game actually invokes this right at the beginning when your PDA reboots in emergency mode. Instead of giving you the run-down on what to do after your life pod just crash-landed on an uncharted planet, it simply advises you to read the relevant database entries. Most of what it tells you as the story progresses is similarly useless from a utility perspective, and nearly everything important to your survival must be gleaned from text messages.
• The Artifact: Downplayed, regarding the Reaper Leviathan skeletons in the Inactive Lava Zone. The explanation is that the Sea Dragon Leviathan dragged them down from the Crash Zone, except direct travel to the Crash Zone from the ILZ seems impossible through natural means, as this is a leftover from Early Access builds ^note which would've exposed the ILZ to the surface in the Crash Zone and Dunes. However, there is the Lost River entrance in the Bulb Zone, a very large tunnel that goes straight to the Disease Research Lab and has a large pit connected to the Inactive Lava Zone, which would allow the Sea Dragons to leave and capture the Reapers living in the Mountains biome adjacent to the Bulb Zone).
• Apocalyptic Log: Abandoned PDAs from the other Aurora survivors, as well as those of the Degasi crew, can be found in the various ruined life pods and seabases, detailing their owners' respective plights.
• Are You Sure You Want to Do That?: The PDA asks you this the first time you enter the Dunes.
  PDA: Detecting multiple leviathan class lifeforms in the region. Are you certain whatever you're doing is worth it?
• Arm Cannon: The P.R.A.W.N. suit features mounting points for subsystems on both of its arms, which can be fitted with a Propulsion/Repulsion Cannon or Torpedo Launcher.
• Attack of the 50-Foot Whatever: Hostile Leviathans in a nutshell. There are six Leviathan-class lifeforms in the game, three of which are aggressive, and the smallest of these - the Reaper - measures 55 meters in length (your largest vehicle sits at 54m/177ft). It's dwarfed by the adult Ghost Leviathan's 107m (even the juveniles are bigger than Reapers at 67m) and the Sea Dragon with its 112m. The game's largest creature, the Sea Emperor, is estimated to measure 160-200m in length, although thankfully it doesn't attack you.
• Base on Wheels: The Cyclops is an underwater variant, big enough to be a home in its own right and, more importantly, considered a valid target to build on, allowing you to install storage, growbeds, and other amenities that make it function as a mobile home.
• Bittersweet Ending: Good news: You've been cured of the lethal bacteria you and the rest of the planet are infected with, shut down the alien cannon built to keep the planet quarantined, and built a rocket ship to escape. Slightly less good news: The Big Good Gentle Giant who helped cure you is about to die of old age. She's okay with this, though, since you helped her babies hatch and they'll spread the cure to the rest of the planet. Bad news: You're the only survivor of your ship getting shot down by the cannon, and another ship that came to rescue you was also shot down, killing everyone on board. Even worse news: You make it home, but the MegaCorp you work for preemptively claimed ownership of all the planet's resources. Which you've been picking up and using to build everything you needed to survive. Which means they won't even let you land until you pay off the massive debt you now owe them. Which is around one TRILLION credits.
• Book Ends: The game opens with a panel breaking loose in the protagonist's Lifepod, striking him in the face and knocking him unconscious. Another panel breaks loose in the Neptune rocket as it passes through the orbital debris field, but this time the panel misses the protagonist, leaving him conscious for the epilogue.
• Border Patrol: Adult Ghost Leviathans spawn in the Void/Crater's Edge, with even the PDA saying exploring said biome is "not recommended." At a sufficient distance, if you somehow survive, you'll allegedly be teleported to Lifepod 5.
• Brick Joke:
  • The first time you pick up a diamond, the PDA explains that everything on the planet is the property of Alterra and that you will be billed for everything you used, with the bill running at three million credits. Come the Stinger after the credits roll, You have made it back safely, but Alterra refuses to allow you to land your rocket until the debt you owe for the resources used on 4546B is paid, which is now at a grand total of a trillion credits.
  • On said escape rocket, upon exiting the atmosphere you enter a debris field from the Aurora. A panel breaks off and the protagonist raises their hand defensively, having learned about getting smacked in the face by loose panels from the prologue.
• Charged Attack: The Seamoth perimeter defence system unleashes a powerful electric pulse that stuns and damages nearby creatures, up to and including Leviathans. Holding down the fire button continually increases the pulse's range but consumes ludicrous amounts of energy (up to 15% of the sub's power cell at full power; a standard shot consumes 1% to fry everything in a ten-meter radius).
• Chekhov's Gunman: The Peepers. Being such a common prey animal makes them perfect for transporting the Sea Emperor's Enzyme 42 out of the Primary Containment Facility and into the local ecosystems, thereby saving most of the local fauna from dying of Kharaa.
• Closed Circle: You are trapped on the planet due to the destruction of the Aurora until help can arrive. Taken even further when your rescue ship is shot down by a planet defence laser meant to quarantine the Kharra bacteria from escaping the planet. Leaving at that point requires not only constructing a new space ship but finding a way to cure yourself (and the rest of the planet) from the infection to disable the cannon.
• Colony Drop: A meteor fell on Planet 4546B in the Dunes 1,000 years ago, which is implied to have had long-lasting effects. The PDA implies that the meteor is what started the extinction event on the planet. The Kharaa only made it worse.
• Cool Boat: All of the craftable ships, but the crown of this trope goes to the Cyclops submarine, which is also a mobile seabase for the player.
• Cool Starship: The Aurora, which ends up exploding, giving you entry, and placing a burden on you to repair the reactor containment field, or else the ecosystem will be overrun by deadly radiation.
• Creature-Breeding Mechanic: You can breed fish as long as you have two to start with and an alien containment unit to place them in. This is useful to create a steady supply of food or bioreactor fuel.
• Crew of One: In-Universe, a selling point for the Cyclops is that, despite being designed for a crew of three, it can be operated by a single person if the need arises. This has made it very popular among deep-sea exploration teams and is a tremendous boon for the player.
• Curb-Stomp Battle: Unless you have a P.R.A.W.N. suit with the drill upgrade, a confrontation with any hostile creature larger than yourself will almost inevitably be this. Your only real option is to flee. Subverted with some players, who have, similar to Marguerit, taken down leviathans with just the stasis rifle and knife.
• Cute Machines:
  • The Seamoth is what you'd probably get if Apple were to branch out into submarine construction. It's small, it's almost completely spherical and just all-around adorable to behold.
  • The head-sized construction drones that come with the Mobile Vehicle Bay and the Neptune rocket launch platform are another excellent example.
  • The alien robots you can find in two of their facilities, which resemble cute little metal bugs◊ with curious eyestalks. Although aggressive, they are basically harmless to you. They will also climb on your PRAWN suit.
• Deadly Gas: Gasopods can produce gas pods that explode after a short while to create a deadly, yellow-green cloud. If the player is quick, they can grab one or two pods before they pop and use them to create gas torpedoes.
• Death of a Thousand Cuts: Hostile Leviathans have between 5,000 and 8,000 health. Your knife does 20 points of damage per swing, 40 with the Thermoblade upgrade. A fully-charged stasis rifle shot will pin a target in place for 30 seconds. It is entirely possible, if time-consuming, nerve-wracking, and extremely dangerous, to keep a Leviathan pinned in a stasis field while you saw at its neck with your knife, occasionally stopping to reapply the stasis effect, until it's finally dead.
• Death World:
  • The Dunes biome is home to eight Reaper Leviathans, and entering it will prompt the PDA to specifically ask you if what you're doing there is worth the risk.
  • The Crash Zone will kill you in under a minute if you enter without a radiation suit following the drive core of the Aurora exploding and is also stalked by ten Reaper Leviathans. Unlike most of the other deadly biomes, players can enter the Crash Zone very early in the game, forcing them to face Reaper Leviathans without the Seamoth's perimeter defenses or PRAWN suit.
  • The Mountains is home to the remaining seven Reaper Leviathans, not to mention a lot of Warpers.
  • The Bulb Zone is teeming with Bonesharks and Ampeels, who will frequently attack you and your Seamoth as you traverse the region. You definitely don't want to linger long without a fully-charged repair tool and at least one medkit.
  • The Crater Edge surrounding the Crater is an ecological dead zone that contains only two forms of life: microscopic, and Leviathan-class. If you enter it, up to three Ghost Leviathans will appear and chase you relentlessly until you're dead or out of their territory. The PDA implies that this biome spans much of the planet.
  • The Inactive Lava Zone and Lava Lakes are scorching hot, home to Lava Lizards and Sea Dragon Leviathans, and infested with Lava Larvae that drain electricity from your vehicles, potentially leaving you stranded a kilometre underwater. Visibility is also low, making it difficult to find your way out even if you do still have power.
• Deflector Shields: An upgrade for the Cyclops gives you one. The bubble effect only covers the forward canopy, but the effect is around the entire sub. It zaps Lava Larvae, renders the sub invulnerable to damage from even a persistent Sea Dragon, and also seems to prevent pressure from crushing the hull. Too bad it drains power like nobody's business. It's required to build the Neptune Escape Rocket, as it allows you to survive the orbital debris field.
• Derelict Graveyard: The volcanic crater/plateau that the Aurora crashed on is one, albeit it only consists of a single ship. Most of the Aurora landed in a large wreck that looms partially above the water, but large sections of the ship detached either during its fall or on its impact, sending entire deck assemblies scattered about the ocean floor. Many of these still have their interior compartments relatively intact, and salvaging them is useful for basic supplies and essential for unlocking additional blueprints.
• Developer's Foresight:
  • If, by some absolute miracle (or use of console commands or simply not repairing the radio until the end), you manage to shut down the Quarantine Enforcement Platform before the Sunbeam arrives, not only will the ship not be shot down, but Captain Quinn will send you a unique message about being unable to penetrate the immense orbital debris field left behind by the attack on the Aurora.
  • If by some other absolute miracle, you manage to fully scan a Reaper Leviathan without getting Eaten Alive, the data bank entry will contain a motivational note from your PDA to congratulate you on your unlikely success.
• Difficult, but Awesome: The Cyclops and PRAWN. They are essential for the depths of the late game where the Seamoth can't go, pack a punch, and have high customization options. They are, however, also slow and bulky and energy-draining, lacking the scouting qualities of the Seamoth. Specifically, compared to the 360-degree mobility, the Cyclops handles like a shopping cart the size of a bus, and the PRAWN suit - whilst boasting impressive armour - has little to no vertical maneuverability, making it easy to jump off an edge and spend a lot of time crawling back up.
• Dishing Out Dirt: More or less the purpose of the Terraformer before it was removed for technical and gameplay purposes.
• Doomsday Device: While exploring the Quarantine Enforcement Platform, you can scan a malfunctioning one. Despite being small enough to hold in your hands, the data readout indicates it packs enough oomph to destroy the entire solar system.
• Door to Before: Some of the alien arches connect the deeper parts of the map with the surface. Naturally, you can't activate them until you reach the depths yourself.
• Dying Alone:
  • The protagonist is at risk of this. From data downloads, it is known or implied that this has happened to almost everyone who didn't die in the crash.
  • This is the ultimate fate of the Sea Emperor Leviathan. After clinging to life for far longer than her natural span, she sees her eggs hatch and her children escape their prison, seemingly knowing that she will not be able to follow them. From her communications to the protagonist, she seems to accept this fate peacefully.
  • Datapads reveal this to be the fate of Paul Torgal, as well as his son Bart. After the Leviathan attack on the Degasi survivors' deep-sea base, Maida fights the creature and is last seen going off into the darkness while tangling with it, and Bart is nowhere to be found, leaving Paul to drown or bleed to death alone in the depths. A separate datapad on the Floating Island reveals that Bart returned there alone and eventually succumbed to the Kharaa infection.
• Earn Your Happy Ending: For both the player and the mysterious race known as the Architects. In the player's case, after fighting through a world full of dangerous creatures and leviathans, being infected to an advanced stage of The Plague, and losing a trading vessel for their sake, they construct a rocket and escape. For the Architects, although they lost the one thing that they really wanted to protect, it brought forth a new generation of Emperors that will produce the enzymes necessary to finally cleanse the planet of the bacteria, and will soon no longer have the need to shoot down any more ships.
• Easter Egg: Several wrecks and even the Aurora contain Natural Selection 2 posters, which you can pick up and hang in your base.
  • Formerly the sound designer/voice of the protagonist slipped in a joke when boarding the Seamoth. "I love it when you come inside me.
  • While rare, the Cyclops's AI will announce that "You are the best captain on the planet, I'm not even squidding.
• Easy Logistics: Subnautica being a survival game, it heavily averts this. Keeping yourself alive and your base running requires careful planning and consideration not only about how, when and where to invest your scarce resources but also about figuring out where to find them first.
  • The two most powerful and reliable reactor models in the game must be provided with a constant fuel supply. If they run out, your base including its oxygen production simply stops working.
  • Mounting longer expeditions necessitates sacrificing generous parts of your limited storage capacity for vital supplies like food, water, batteries, medkits and tools, all of which need to be crafted from varying amounts of resources. This naturally limits the amount of salvage you can carry home from your trips, making storage capacity upgrades in your vehicles quite helpful during mining forays.
  • A major part of the benefits of advanced technology is that they reduce the strain on your supply lines. Alien containment tanks allow for the breeding of fish that can be eaten or used as bioreactor fuel. Planters are invaluable for growing even more food and biofuel, as well as crucial crafting resources that otherwise require venturing deep into the game's most dangerous areas. Water purificators provide you with a limitless supply of high-quality water, plus salt for crafting food rations without an expiration date.
  • One of the few aversions is the repair tool. You don't need actual resources to repair stuff, only a charged battery in the tool.
• Effortless Achievement: The full release still has a few of these. Getting your feet wet and consequently building your first base piece, which takes a little effort. You'll unlock achievements for building the three currently implemented vehicles and exploring story-required locales. Building the escape rocket and launching the time capsule are also achievements. The Neptune is pretty resource heavy, but the time capsule is literally a button press to launch, and usually launches automatically with the rocket's ignition.
• 11th-Hour Superpower: The penultimate story objective contains blueprints for Ion Batteries and Ion Power Cells, which provide five times as much juice as their basic counterparts. A Repulsion Cannon with such a battery installed doesn't deal more damage but can fire 100 shots before needing a reload, and the Cyclops' power reserves become so vast that activating the Deflector Shields or the Silent Running mode causes much less of a headache than it did before.
• EMP: The crabsquid's signature attack, capable of temporarily disabling anything electric in a considerable radius. Trying to get away from two or more Crabsquids in any vehicle will make you feel like you're stuck in a stop-motion movie shooting.
• Empty Room Psych: Downplayed but present in the Void, the bottomless abyss around the crater that constitutes the game world. There's absolutely nothing there except water, darkness, and silence... and an army of Ghost Leviathans just waiting to tear you to pieces if you dawdle in their territory for too long.
• Enemy-Detecting Radar: The Cyclops submarine is equipped with one. It will display the location of large creatures relative to the vehicle, and hostile creatures are shown in red.
• Everybody's Dead, Dave: By the time the main game's events begin, every mentioned character except the player and the Sea Emperor are dead or missing.
• Exactly What It Says on the Tin:
  • The scanner data for the pink mushroom describes it as "definitely a mushroom". Most of the names of the fish are pretty descriptive as well; the Boomerang indeed just looks like a boomerang.
  • This gloriously helpful item description: "Fire extinguisher: extinguishes fire." Who'd have thought?
• Fast-Killing Radiation: After the crash of the Aurora, the reactor is severely damaged and will spread radiation throughout a large area until you fix the reactor. This will rapidly deplete your health, but can be healed with a normal health pack or simply protected against by the easily acquired radiation suit.
• Flower Mouth: The Mesmer has a mouth that splits open four ways to reveal four tentacle-like appendages lined with teeth that lead to its actual throat.
• Fragile Speedster: The Seamoth is the fastest mode of transportation in the game^note The Prawn suit can move notably faster with its grappling arm, but it requires a specialized upgrade and good timing, but a few collisions with the environment or attacks from aggressive fauna is enough to turn it into a pile of scrap metal.
• Friend to All Living Things: The Sea Emperor. She's entirely harmless, the normally predatory species living in her enclosure are peaceful, and she's actively trying to fight the infection of the planet.
• Forbidden Zone: A few would qualify, but the Crash Zone is a prime candidate. Reaper Leviathans hunt in the surrounding seafloor, and after the Aurora's reactor containment field explodes, the area fills with radiation and cannot be explored without a radiation suit.
  • Then there's the Crater's Edge, AKA the Void, aptly named because the seabed steeply dives into an inky abyss and it's populated by multiple Ghost Leviathans who want nothing more than to eat you and your Cyclops.
• Foreshadowing: You'll encounter small pink creatures called Floaters who have attached themselves to small rocks in the Safe Shallows. You can eventually find a huge island, as well as smaller underwater islands, being held afloat by huge versions of the same creature.
  • After you repair the escape pod the status display says that the bacteria count in the water is high. This turns out to be a major plot point.
  • One of the first items the player can craft is a short-range scanner. After a while, you can scan yourself a second time, the display on the scanner reads "INFECTED".
  • The first data file on Peepers mentions they have a pointlessly enlarged nasal cavity designed to detect a single, very specific enzyme that absolutely nothing yet encountered produces. You can also spot Peepers emitting a strange glowing trail, which, if scanned, is coated in some strange substance that inhibits bacterial growth. Said Peepers are also seen exiting and entering strange Alien Vents dotted around the surface. The Peeper's cavity is designed to detect Enzyme 42, and is the first hint of the Emperor Leviathan's deliberate alterations to the Peepers to help it save the ecosystem from the Kharaa Bacterium. Those glowing trails are also streams of unstable Enzyme 42, bestowed upon them by the Leviathan and released via the Alien Vents.
• Fungus Humongous: The Mushroom Forest and Jellyshroom Caves.
• Game-Breaking Bug
  • A particularly nasty persistent bug occurs when you save your game, which causes any partially researched blueprint to lose all progress and forces you to start over. It seems to have been fixed with the full release though.
  • There are still a lot of clipping issues even after the game went gold. The player can often fall through the seabed, even in a vehicle, requiring console commands to warp you away, often at the cost of your vehicle.
  • The P.R.A.W.N. Suit loses almost all of its jet mobility and grappling-arm winch strength while outside of the water. If the player takes the P.R.A.W.N. onto dry land, exits the suit, saves the game, and then re-enters the suit, it can lock the P.R.A.W.N. in the "out of water" state permanently, crippling its limited mobility even when back in the water. The only solution is to build a completely new P.R.A.W.N. Suit. Especially breaking as the P.R.A.W.N.'s jets and/or grappling-arm are almost required to get into the Lava Castle near the end of the game, plus the prawn is advertised as an amphibian vehicle in-game, meaning some players are inadvertently going to try taking it onto land and end up breaking it.
    • A much worse version of this glitch exists where it triggers in the Lava Castle at the Alien Thermal Plant. This has all of the above problems... miles beneath the surface in one of the most dangerous areas of the entire game and can also remove the water physics for the player. As this requires a fully upgraded Prawn to even reach this area, the loss is even more costly than when it happens on the surface. While dying can remove this for the player, the glitch may also remove the damage dealt by the nearby lava, meaning the player can only wait to starve to death or die of thirst. As if this was not bad enough, there's a second glitch where spawning or building a new P.R.A.W.N. Suit results in this glitch carrying over to it. If the player has saved, this effectively renders the game unwinnable.
  • For anyone hoping to use your PRAWN and incredible skills to kill a Reaper leviathan, you should probably give up hope. With the hull reinforcement upgrade a PRAWN might be able to take on a Reaper... except that almost every such battle ends with the Reaper clipping through the terrain and glitching your PRAWN into uselessness, whether trapped in the terrain or dropped thousands of kilometres below the world.
  • Even in the full release, vertical seabase modules are still somewhat buggy, and one particular bug has been in the game a full three years before going gold. Sometimes, if you construct a tunnel compartment, place a vertical module on top, put a Multipurpose Room on top of that, and then try to install a ladder so you can access the Multipurpose Room from the lower compartment, the entire three-module section will sometimes bug out, not allowing the installation of a ladder nor the deconstruction of any of the three modules. Both the compartment and the Multipurpose Room can still be entered, and used, and have some compartments attached to them, but the vertical compartment remains useless, and if you plan on changing up your base, you're out roughly 16 Titanium and have to be willing to either move or work around the stuck modules.
  • Sometimes when you drop something, it falls through the floor. This can be quite irritating, especially if it was a useful piece of equipment.
• Gameplay and Story Segregation: An important factor in what happened to one group of survivors from the Aurora was how they tried to cope with extreme weather conditions. You never encounter anything but calm weather during gameplay.
• Giant Squid: The Crabsquid, which was implemented in the Machinery Update. Oh, and it can walk on the seafloor and produce EMP blasts.
• Going Critical
  • The Aurora's reactor explodes, releasing lethal radiation in the surrounding area which will kill you without a Radiation Suit.
  • If your Cyclops suffers a Critical Existence Failure, you will have about ten seconds to abandon the ship before it explodes.
• Going Down with the Ship: An abandoned PDA reveals that Captain Hollister stayed onboard the Aurora until the very end, knowing that the survivors would need the ship in one piece in order to contact Alterra HQ.
• Grappling-Hook Pistol: One of the PRAWN upgrades. Essential if you're taking it anywhere deep.
  • Fun for latching onto a Leviathan and going for a rodeo ride.
• Greed: Paul Torgal's search for a resource-rich celestial body is what doomed the Degasi and as a consequence the Aurora and the Sunbeam. Justified as mining was his job, and no one could have expected to be shot down by an automated Orbital Defense Platform. His decision to go live underwater near richer mineral deposits (and sea monsters) is more clearly a bad choice instead of just an unlucky one.
• Green Hill Zone: The aptly-titled Safe Shallows is one of the only biomes where the player doesn't have to worry about predators. There are still threats like Gasopods around, but they'll leave you alone if you give them space.
• Grimy Water: Brine flows through the Lost River biome hundreds of meters below the surface. This sulphur-yellow liquid is much denser than seawater, so it settles in streams and pools along the seafloor. Evidently, it is highly caustic, because dipping into it will steadily erode your health.
• Hazmat Suit: The whole of the Radiation Suit, the Radiation Gloves, and the Radiation Helmet. Lack one, and the radiation will harm you.
• Hearing Voices
  • The Mesmer will do this to you if you get too close.
    PDA: It is your primary directive to swim closer to that beautiful creature... Do not resist... Don't struggle...
    • The PDA entry says the pattern on its fins basically makes you perceive the most trustworthy source to tell you the above message. In the protagonist, that's obviously the PDA. Makes one wonder what the other fish hear/perceive.
  • Your first encounter with the Sea Emperor is hearing its voice from nowhere. It's later shown that it speaks to you through telepathy.
    What... are... you?
• Hell Is That Noise
  • The radio's beeps whenever it picks up a new message. The first few messages you get are distress signals from fellow survivors. As you go to explore, which is needed to continue the story and get more messages, you'll find out they all already have died. From that point on, the beeping becomes a grim reminder because you know it won't lead you to survivors but to their final PDA files often giving a good idea of how their final moments were. Then after a while, the radio starts picking up on messages that aren't from fellow survivors but from Warpers hunting for them. And for you.
  • It's not unusual to hear creatures before seeing them. The Reaper Leviathan's PDA entry ups the discomfort of its roar with the following line: "The deep roar emitted by the reaper at regular intervals is effectively sonar - if you hear it, the reaper can see you." Now consider that reaper roars can be heard up to half a kilometer away from them...
• Hoist by His Own Petard
  • The player can do this to themselves if they breed Crashfish and then set them loose outside their base. Sure, the fish won't attack you because it grew up docile, but it will attack other fish by suicide bombing them right next to the hull of your base, causing a breach, a flood, and a panicked flail as the player runs all over trying to find the hole. Why, no, this isn't inspired by a true story at all...
  • The Prawn Suit's grappling hook can be used to hitch a ride on Leviathans. While this can be quite entertaining, doing it to a Reaper will radically and permanently alter its patrolled area as it tries to shake you off. It's not uncommon for the beast to end up in a completely different biome including the Safe Shallows this way, and possibly way too close to your base for comfort. Players have reported up to three Reapers taking up residency barely 100 meters from their base because of this.
• Homing Projectile
  • Torpedoes will, if a Leviathan is present, immediately home in on them to the exclusion of anything else. Given how immensely dangerous Leviathans are, this is an extremely welcome quirk.
  • The spikes shot by Tiger Plants are semi-homing as well, capable of adjusting their flight path to a moderate degree.
• Hope Bringer: The protagonist. Almost by accident, they complete the Architects' work of saving the Sea Emperor population and stopping the Kharaa epidemic.
• Hope Spot:
  • Another ship, the Sunbeam, picks up the emergency distress signal from the Aurora and comes to help... only to share the Aurora's fate, being blasted out of the sky by the Quarantine Enforcement Platform. There are no survivors this time.
  • Data from the Quarantine Enforcement Platform mentions a Disease Research Facility, which sounds like your best bet for finding a cure for the Kharaa infection. But when you find it, the facility has been in ruins for a long time. There is no cure to be found there; in fact, the place was ground zero for the outbreak.
• Improvised Weapon: The developers (and, In-Universe, the Alterra company) intentionally made the game lack true weaponry besides torpedoes, but that doesn't stop particularly paranoid or violent players from taking revenge against the sea life.
  • The Propulsion Cannon, originally designed as a short-range logistical tool, can be used to grab and toss crates at sealife or to pick up smaller creatures and slam them against walls for lethal damage. There's also a variation on a PRAWN Suit's onboard storage to give it a sort of ammo magazine.
  • The Repulsion Cannon upgrade for the Propulsion Cannon completely removes the ability to pick things up, going directly to blasts of force. Of course, this is intended as a self-defense tool to get away from animals, but it's still quite easy to smash a shark against the sea bed multiple times until it dies.
  • In the same vein, the Drill Arm is primarily an industrial harvesting tool, but three shrieking and grinding blades are remarkably handy for convincing a hungry Reaper Leviathan to seek out easier prey when applied vigorously and mercilessly.
  • Even the default Prawn Suit arms are quite powerful. A few punches to a Stalker will very easily kill it, even when the arms' primary use is to pick up resources without getting out of the suit.
  • Even torpedoes are supposed to be non-lethal, with the standard Vortex Torpedo merely creating a disorienting water vortex to confuse predators. Mix in some Gasopod poison, however, and you get lethal gas torpedoes.
• Interchangeable Antimatter Keys: Alien Tablets universally unlock consoles that match their color, regardless of where they were found, and can't be retrieved from the console afterwards.
• Killed Offscreen: At one point, the radio intercepts a piece of inter-Warper communication stating that there are nine Aurora survivors unaccounted for. Soon thereafter, another communique states that there's only one of them left (guess who), implying that the rest are being eliminated while you're doing whatever.
• Last of Her Kind: The Sea Emperor is the last of her kind before her young hatch.
• Last-Second Joke Problem: In The Stinger, the player is welcomed home to Alterra, but is denied permission to land until they've compensated the company for all the resources they collected and used while marooned on 4546B... which amounts to one trillion credits.
• Late to the Tragedy
  • Seconds after the protagonist escapes the Aurora, they are knocked out cold by a loose panel. They are unconscious for a few hours and by the time they wake up, all other people who made it off the ship have already perished. And that's to say nothing about what happened on Planet 4546B in the first place.
  • The presence of a meteor in the Dunes and some of the PDA's suggestions imply the Architects qualify for this trope as well, and releasing the Kharaa only rubbed salt in the wound.
• Lethal Lava Land: The Inactive Lava Zone and the Lava Lakes. And they are underwater!
• Lightning Bruiser: Reaper Leviathans, full stop. They can swallow the player whole, can crack a Seamoth in two hits and players are physically incapable of outrunning them.
• Macguffin Super Person: The Sea Emperor, who is contained in the deepest and most dangerous part of the map, is the only source of the cure for the Kharaa Bacteria. Helping it hatch its babies so they can cure you and release it to the rest of the planet not only saves all life on the planet but is also required to disable the Quarantine Enforcement Platform and leave the planet.
• Minimalist Cast: The player character is the sole human on the planet, and the other alien species there seem to be fairly normal animals in terms of intelligence.^note This is why the character sheet is really more of a bestiary. You can eventually find some old notes from previous crash survivors, but the state of their bases should be more than enough to tell you that they're long gone.
• Mood Whiplash: Appears in the soundtrack. Most of the songs are appropriately mellow for a game that predominantly takes place underwater, but upbeat, hardcore EDM plays whenever the Cyclops is critically damaged or goes up against a Leviathan-class predator.
• More Teeth than the Osmond Family: Stalkers, but it's cool because you need the teeth and they've got an endless supply of them. Sand Sharks have several rows of teeth going down into their throats.
• The Mothership: The Cyclops is a moderate, species-inverted example by virtue of being a player-controlled mobile base that also features an internal dock for carrying one smaller vehicle (Seamoth or Prawn, obviously).
• Murderous Malfunctioning Machine: The distress call from Lifepod 7 mentions that their emergency fabricator is malfunctioning. If you find the lifepod, you can see the results: instead of producing any useful survival equipment, it fabricated a bunch of useless junk (including pens, microscopes, a toy car, and a Markiplier doll). While this didn't directly harm the Lifepod's occupants, it probably sealed their fates.
• Names to Run Away from Really Fast: Reaper and Ghost Leviathans, though by the time you get close enough to discover their names with the scanner, it's probably too late for that. Stalkers also count, although they're far from the most dangerous thing in the ocean.
• No Body Left Behind: Despite having 157 people on board, not a single shred of a body can be found in the game. No blood splatters, no bones, no clothing scraps, no nothing. Meanwhile, several wrecks contain potted plants that got through the crash in one piece. Justified as the Warpers killed all of the survivors. And if it's the latter, their scythe-like arms are definitely sharp enough to avoid leaving behind tangible amounts of remains. Also, the PDA mentions that many indigenous lifeforms in and around the Aurora have trace elements of human tissue in their digestive tracts, so whatever remains did exist were simply eaten by the local fauna.
• No-Sell:
  • Once a Reaper or Sea Dragon Leviathan has grabbed your vehicle, there's little you can do to make them let go. Shoot torpedoes into their face point-blank, grind the Prawn's giant drill into their forehead as much as you want, the beasts couldn't care less. Only one thing in the game can save your butt in this situation: the Seamoth's perimeter defence system, but unfortunately, the Seamoth isn't rated for the depths where Sea Dragons are encountered.
  • Ampeels and Crabsquids are unaffected by the aforementioned Seamoth perimeter defense system, probably because they utilize electric attacks themselves.
  • The reinforced diving suit makes you immune to the Tiger Plant's spike bombardment, and the 50% damage reduction it provides on top of that enables you to tank a lot of attacks that would've nearly killed you otherwise. It also increases your temperature threshold before you take thermal damage to 70°C, which is sufficient protection to swim around even in the Lava Lakes with impunity as long as you don't get too close to the actual lava.
• No Ontological Inertia: The Cyclops has a peculiar case of this. Even when its hull is at critically low integrity, the inside is on fire and an angry sea monster is beating on it, if you leave the vehicle BEFORE the AI starts the Catastrophic Countdown, the Cyclops will remain perfectly intact, albeit filled with smoke and covered in gaping holes. It's only after you re-enter the vehicle that the vehicle's destruction resumes.
• Nothing Is Scarier:
  • The Dunes and the Mountains biomes. Once you transition there, the music stops and all ambient noise goes quiet, save for the players. All the better to hear the distant screams of Reapers.
  • It's even worse in the Void - no music, no fish, no sounds, no sea floor. Just endless ocean and inky darkness all around you. And then the Ghost Leviathans show up.
• Offscreen Moment of Awesome: It is heavily implied that the survivor on board Lifepod 4 managed to get close enough to a Reaper Leviathan to scan it without being eaten and even without access to a stasis rifle. Unfortunately, he then tried to swim back to the safety of the Aurora wreckage; either his luck with the Reapers didn't hold out or he succumbed to the radiation or reached the ship only to perish in the drive explosion.
• Oh, Crap!:
  • The traditional reaction to a player hearing any of the distinctive roars that signal an imminent encounter with any of the three aggressive Leviathan species.
  • Also the likely reaction of a player being in a position to witness the demise of the Sunbeam for the first time. Its proposed landing site is right outside the Quarantine Enforcement Platform, which resembles a curious alien tower when idle. Right before the hapless ship enters the atmosphere, the Platform begins to emit an alarm and starts changing shape. Before too long, the player will realize it's beginning to resemble a colossal gun turret. One that is now tracking the approaching Sunbeam...
• One-Hit Kill
  • The Reaper Leviathan will grab you with its giant mandibles, roar, and swallow you whole if you're under 80 health and outside a vehicle. Speaking of which, it can grab Seamoths and PRAWN suits and throw them against the ocean floor, destroying them in one hit.
  • The Sea Dragon Leviathan can eat you alive. It is exactly as terrifying as it sounds, and ten times worse if you witness it while playing in VR. It's one saving grace is that it's so large it's possible to escape its notice.
  • The Quarantine Enforcement Platform, AKA the cool-looking alien structure where the Sunbeam is scheduled to pick you up for evacuation, is actually a giant anti-orbital weapons platform that does this to any ship that enters its firing range. It brought down both the Degasi and Aurora in one shot and does the same to the Sunbeam, only the latter explodes right away without even a chance of performing an emergency landing.
• Open Mouth, Insert Foot: The first message you get from the Sunbeam has Captain Quinn cynically remark that you're probably just abusing the Charter (a treaty that requires other ships to provide aid to a ship in distress) to get nonessential supplies. The second time, he's spotted all the debris and realized the full extent of the disaster, and his tone very much suggests that he regrets making light of your situation.
• Our Dragons Are Different: The Sea Dragon. It has a reasonable upper body of an aquatic dragon, plus squid legs.
• Our Fairies Are Different: Rockgrubs are basically aquatic fireflies.
• Palette Swap: There are currently five creatures that are a texture swap of other creatures: Crimson Rays to Ghostrays, Blighters to Biters, Spinefishes to Hoopfishes, Lava Boomerangs to Boomerangs, and Lava Eyeyes to Eyeyes. The game also includes a few models that are not texture swaps but still very close in appearance to other models, such as Jellyrays and Ghostrays and Blood Crawlers and Cave Crawlers. Creatures part of the design repeats are explained to be genetically related.
• Percussive Maintenance: When trying to free himself from the chair in the escape pod in the beginning, the protagonist presses the release button several times to no avail. So he slams his fist down hard on the panel in frustration, which naturally works.
• Piranha Problem: Biters and Blighters, which hunt in small schools and chase you from further away if your health is low.
• Portal Network:
  • The reason why the Aurora was near 4546B was that it had visited the system to construct a phasegate here (though given no one mentions going into cryosleep or anything of the like, it seems more "conventional" FTL travel is also a thing).
  • The Architects have created an entire network of portals on the planet's surface, connecting both islands as well as various facilities. By the time you arrive, they are shut down to stop the Kharaa from spreading - although they can be restarted from the Primary Containment Facility. The PDA describes them as miniature phasegates.
• Power Crystal:
  • Ion Crystals, used to activate Alien Arches and craft Alien Tablets.
  • Also Kyanite crystals, to a lesser extent, which are used in crafting some of the most powerful vehicle upgrades. Kyanite is a real material with industrial use that is indeed highly heat resistant. While not "powerful" in the mystical sense, they certainly do make some of your stuff more powerful.
• Powered Armor: The Reinforced Dive Suit and the PRAWN qualify - the latter especially, as in addition to making you very tough to kill, it provides an infinite supply of oxygen, and increases your speed. Also, if you mount the grappling hook, it allows you to move around much faster than swimming with just fins. The PDA even warns you against going on a power trip the first time you use it.
• Precision F-Strike:
  • In a log file on the Habitat Update's webpage.
  Controller: (responding to the Aurora’s survival PDAs running version 1.0) Bring me every star chart, tech geek and concentration enhancer in the building...
  Analyst: Yes Ma’am!
  Controller: ...and god DAMN it you build me an update package, and you find me a way to flash them Version 1.1!
  • And later, this on the Seamoth Update's webpage.
  Controller: Ship [the survivors] the Defense System and the Vortex Torpedoes.
  Analyst: But ma'am, weapon designs violate directive 7!
  Controller: Directive 7 is there to eliminate the risk of survivors turning on one another. If they're going fin-to-fin with alien krakens then they have bigger fish to fry. I want them prepared, and damn the directives!
• Recoil Boost: In a non-weaponized example, spraying the fire extinguisher underwater will cause you to move backwards. Slowly, yes, but it can be a fun distraction. Above water (i.e. in your base or the Aurora), there's naturally no recoil, as your feet are firmly planted.
• Refuge in Audacity: Going straight towards certain aggressive creatures and attacking them with your knife, or ramming them with your vehicle is sometimes the best way to deal with them.
  • In the same vein, trying to kill a Reaper Leviathan is very risky, long and difficult, but hopefully, you have the Stasis Rifle to help you out, and as a great payoff, they will never respawn again once they're dead, making exploration of certain areas much safer for the rest of the game.
  • Scanning the more dangerous leviathans without any tools to aid you cannot be done unless you are insanely lucky, or insanely audacious. The best way to get the upper edge in avoiding the bites long enough is to provoke them first, and then not make the mistake of pressing backwards- but left or right, because the Reaper and most other creatures cannot turn whilst gnawing at you fast enough, meaning you'll just be slightly out of their reach. In short, it is preferable to just go up to them, dance the tango with them, and scan them while going in circles if you can keep your blood pressure down. Have fun testing that, though!
• Retractable Weapon: How the Quarantine Enforcement Platform innocuously disguises an energy weapon capable of felling a flying city like the Aurora in a single shot.
• Ribcage Ridge: The Bones Field in the Lost River area contains the remains of the Gargantuan Leviathan, a skull larger than a Reaper Leviathan and the first one-third of the creature's body consisting of its upside-down ribs extending through the chamber. A couple of much smaller versions of the same skull and bones are located in two other areas of the Lost River, along with other random spinal columns and ribs. The skeleton of a Sea Dragon Leviathan rests on a plateau in the Junction corridor. It's basically the undersea equivalent of an Elephant Graveyard, and there is Truth in Television, as underwater cavern systems can trap animals that go into them (your PDA even warns you about this fate).
• Robinsonade: After a shipwreck, you are stranded on a deserted planet and must survive alone.
• Scenery Gorn: In marked contrast to the unbelievably gorgeous rest of the game world, the Crash Zone looks more like Mordor than anything else. The crash of the Aurora has torn up the seafloor and turned this area into a brownish wasteland almost entirely devoid of plant life, but hey, at least you've got eight Reaper Leviathans keeping you company.
• Schrödinger's Gun: Depending on when you cure the Kharaa, there's a sufficiently dense debris field that prevents the Sunbeam from rescuing you.
• Scripted Event: Radio messages and PDA log files. The explosion of the Aurora and the Sunbeam being shot out of the sky both qualify as a Video Game Setpiece.^note Slightly subverted with the Sunbeam event- if you delay viewing it until you have cured the planet of the Kharaa virus and disabled the quarantine platform gun, they still won't rescue you, but at least they live to see another day.
• Sea Mine: The Anchor Pods all over the Grand Reef resemble spherical mines chained to the sea floor. According to the databank, they explode and scatter spores when they get tall enough, though this never actually happens in-game.
• Send in the Search Team: What the Sunbeam is to the Aurora. It's later revealed that the Aurora was itself this to the Degasi, albeit as a secondary mission.
• Sequence Breaking: Nothing forces you to repair the radio in Lifepod 5, and it's entirely possible to play through the game without the numerous hints you normally get by listening to the frequent radio calls. However, doing so results in missing several key events and important plot points, like the Sunbeam getting shot down by the Quarantine Enforcement Platform, or receiving the code for the Aurora cabin containing the Neptune blueprints. Once you repair the radio or build a new one, all the messages you missed will still be received one after the other, only with a lot less context and even less actual use to you. However, not getting the Sunbeam event until after you've cured the planet of the Kharaa virus and disabled the quarantine platform gun would result in a happier ending since they won't be shot down and killed by the quarantine platform canon, only refusing to rescue you due to the debris field in the way. Unfortunately, Below Zero shows that the Sunbeam being destroyed is the canon event.
• Shipwreck Start: The game begins with the destruction and crash landing of the starship Aurora, with the rest of the plot spent trying to escape the planet you've been stranded on.
• Shock and Awe:
  • The Ampeel uses this, similar to a real-life electric eel.
  • The Seamoth's Perimeter Defense upgrade, which is more realistic.
• Sickly Green Glow: The Lost River biome is defined by highly concentrated brine rivers that, probably thanks to the Rule of Cool, glow an eerie green. Like most video game liquids that look like this, the brine even acts much like acid when you touch it, but at least it's not radioactive.
• Solid Gold Poop: Sea Treader dung can be collected and used as biofuel.
• Space Is an Ocean: The Seamoth mini-sub is classified as a "one-person sea-and-space vehicle". Sadly, the player doesn't get a chance to put the "space" part to the test, but at least it handles marvellously underwater.
• Spike Shooter: The Tiger Plant, which you can also grow yourself.^note Tiger Plants in an exterior growbed will still attack the player, but there are ways to make it safe to grow Tiger Plants. Their spikes do no damage to the Seamoth or the PRAWN Suit, and the Reinforced Dive Suit deflects them. So if you have any of those, you can feasibly set up several as perimeter guards to your base. They also will not shoot spikes when grown in Alien Containment.
• Status Effects: You get a poison effect when in contact with Drooping Stingers or the Gas Pods from Gasopods. Escaping the contact will return all the health lost.
• Strong Enemies, Low Rewards: It's possible to kill the gigantic Reaper, Ghost and Sea Dragon Leviathans, which requires considerable effort in the first place due to the game's near-total lack of lethal weapons encouraging the player to creep past or otherwise avoid them. However, the only benefit in doing so is the fact they don't respawn, with the creatures dropping no resources or loot of any kind when killed, making slaying them usually a waste of time.
• Sub Story: The Cyclops in particular.
• Surprisingly Realistic Outcome: A humorous example. When Ryley finally deactivates the Quarantine Enforcement Platform and gets stabbed in the arm again, he reacts by punching the console in anger. It is a massive slab of super-hard material, so the only result is that he hurts his hand.
• Swallowed Whole: This happens after the aforementioned Reaper Leviathan catches you with less than 80 health. Also one of the ways the Sea Dragon Leviathan can seal your doom... if it doesn't roast you with its fire breath first.
• The Symbiote: The Crashfish and the Sulfer Plant, as well as the Crabsnake and the Jellyshroom.
• Take Your Time: The game very heavily implies that you will die after about five weeks, thanks to exposure to the Kharaa bacterium and that symptoms should start appearing around two weeks in. Instead, the disease's progression is entirely event-based, and the player will never fatally succumb to it. Slightly justified, thanks to the presence of Peepers spreading diluted Enzyme 42, which inhibits the bacterium's growth and progression. For the same reason the Kharaa hasn't wiped out the entire biosphere, it's possible Ryley is kept alive via indirect exposure.
• Tempting Fate: In one of his audio logs, Paul Torgal laments that Maida, the mercenary accompanying the Degasi crew, doesn't believe that things won't get any better and Paul thinks she wants to put their lives in danger and claims that, since humans have spent millennia shackling nature to their will, the planet they're stranded on won't cause them any new problem. Guess what happens to the Degasi crew in the end.
• Ten-Second Flashlight: Downplayed with the hand flashlight, which lasts a fairly long time on a full battery, but not nearly as long as one would expect with all the other high-tech gizmos those batteries can run. Vehicle lights come in two flavors: the Seamoth and Seaglide have a small drain when the lights are on, while the PRAWN and Cyclops provide light for free.
• This Is a Drill: An exceedingly useful modification for the PRAWN is a huge drill arm; specifically, it's a grinder-style drill designed to pulverize large mineral deposits for harvesting, rather than tunnelling through the ground. Unsurprisingly, it also makes for a pretty decent melee weapon in a pinch. Seeing how constructing it consumes a large number of diamonds, the blades are most likely diamond-tipped.
• Threatening Shark: The Stalkers (during development also known as Snout Sharks), Bone Sharks, and Sand Sharks. The former drop their teeth when they chomp on metal, which are used in the fabrication of enameled glass.
• Unbroken First-Person Perspective: The closest to a break is when you control one of the Camera Drones and can see yourself at the console if you have a well-placed window. But even then what you see with the camera is what the character sees on the console.
• Unintentionally Unwinnable:
  • If you hitch a ride on a Reaper Leviathan with the Prawn's grappling arm, the beast will go nuts trying to shake you off, travelling huge distances in the process, and it will permanently stay wherever it ends up once you let go. Reapers treated this way have a strange habit of making a beeline for your base. Play Reaper Rodeo too often and you can find your base besieged by multiple giant murder machines from all directions, making it next to impossible to do anything in the area. If you don't manage to set up another base somewhere else, your game is pretty much over.
  • There exists a glitch in the area around the Alien Thermal Plant that can cause water physics to simply cease to exist for you and your Prawn Suit. All ways to fix it require use of console commands or other methods that the average player won't figure out, and even harder to fix for the Prawn Suit, meaning even if the player manages to fix it for themselves, they're now stranded deep underwater in one of the most dangerous areas of the game. This can also result in the lava at the bottom not being fatal. The most likely outcome is simply the player stuck miles below the surface, unable to drown or swim out, and the only option being to die (by starvation or thirst) and return to their base, losing everything they got and their Prawn. There's a second, rarer glitch that will result in new Prawns having the same exact problem, rendering the game effectively unwinnable if they've saved since it happened.
• The Very Definitely Final Dungeon: The Inactive Lava Zone is located in the deepest parts of the Crater, is only accessible by going through a massive late game area whose entrances are located in the depths of extremely dangerous biomes, has the final crafting materials in the game, is very hazardous to traverse thanks to the constant heat and Sea Dragon Leviathans patrolling it, and leads to the Sea Emperor, who is the key to escaping the planet. While the Lava Lakes are the actual final area accessible, with the Sea Emperor being held captive within, it’s a fairly small area with not much other than the Primary Containment Facility and a Sea Dragon Leviathan.
• Villain Teleportation: Well, Threatening Force Teleportation, anyway. Warpers are Cyborgs with built-in teleportation hardware. They can come and go as they wish. Not only that, but they can teleport you out of your vehicle so they can attack you directly, and warp hostile fauna in on top of you.
• Violation of Common Sense:
  • The Prawn Suit's grappling hook is meant for helping it traverse vertical distances easily and quickly, but despite the "magnetic" part in its description, it can latch on to almost anything. Even Leviathans. There's no benefit in doing so, considering the beast can still fully attack the Prawn, except for the sheer badass factor of playing rodeo with a 50-meters murder machine.
  • In a similar vein, Leviathans can be scanned like any other creature. Needless to say that attempting this even with the help of a Stasis Rifle is extremely dangerous, very likely to get you killed, and ultimately useless because creature scans don't actually do anything beneficial. At least your PDA lampshades it by congratulating you in case you do manage to pull it off.
  • Ion cubes are strange, glowy green artificial crystals the size of a human head that contains as much energy as a tactical nuclear warhead each. Like most mineral-like resources, ion cubes may be found in large deposits, which you can mine by shoving a huge honkin' Prawn grinder drill into the ominously glowing six-foot cluster. Nothing bad happens, but man, there's gotta be a more subtle approach to this sort of business.
• Volcano Lair: The Lava Castle, a massive castle-like rock formation located deep within the Inactive Lava Zone. It's home to the Architects, along with the Lava Lakes directly below it. All of their power comes from the Alien Thermal Plant at the heart of the Castle, and is budgeted into various operations.
• Walk, Don't Swim: As far as creatures go, Cave Crawlers, Blood Crawlers, and Sea Treaders. The player is capable of this too when controlling the PRAWN suit.
• Weapon of Mass Destruction:
  • The ion crystals you find all have the power of a thermonuclear detonation. Subverted in that they are so stable that you would have to take a lot of steps to set them off.
  • Yet this is played very straight with a small, grenade-sized weapon you can find in the Quarantine Enforcement Platform. Presumably constructed in the event of quarantine failure, its energy potential isn't just enough to wipe out the base or the entirety of the local biomes, but the entire planet alongside most of the solar system to boot.
• We Hardly Knew Ye: Every single human and the Architects qualify, but Captain Avery Quinn takes the cake.
• Wham Shot:
  • At the final minute of the countdown to the arrival of the Sunbeam, the strange alien tower at the landing site suddenly begins to move, extending and rotating to track the ship's approach.
  • At a set time after exploring the Quarantine Enforcement Platform, the player sees a sudden vision of a shadowy, four-eyed face and an other-worldly voice asking "What... are... you?" Adding to the shock factor, this event is triggered by a timer, not a location, so it can happen anywhere at all.
• The Worf Effect: Reaper Leviathans are highly dangerous early in the game. In and around The Lava Zones are Reaper skeletons that the Sea Dragon left behind after eating them.
• The World Is Just Awesome:
  • Bart Torgal certainly thinks so, as he articulates in a log aptly titled "This World":
    "I thought it might get claustrophobic, living underwater. Father feels it is. He'd tell me it was childish, but I stare out the window and sometimes I think how lucky I am to see this world up close. Back on the island, I wouldn't have believed the creatures that live down here. The fish, they glow... there's one that's 90% eyeball... Snakes twice the length of a habitat compartment..."
  • The player can also invoke this by building an observatory (which the PDA complains is "imprudent for survival purposes") and using it to bask in the beauty of 4546B. There's even a special musical track that plays whenever the player enters it.
• Yank the Dog's Chain: After everything the survivor goes through, from scavenging for food and water to fending off giant predators, to curing a disease that has plagued the planet for over a thousand years, he finally builds a rocket and escapes, only for Alterra to claim that he owes them one trillion credits for all the resources he scavenged, and they won't grant him permission to land until he pays it. Better hope you can barter off all the information gathered from scanning the items in 4546B, as well as bringing Architect tech back to barter with^note Though even that might not work, since Alterra preemptively claimed everything on the planet was their property to begin with. However, Ryley did everything Alterra's own survival manual told him to do, so trying to force him to pay this debt is not only incredibly dumb, it's something anyone of sufficient clout could use to defend him. Alternatively, plenty of deals could be made for his knowledge and/or rights to his story in exchange for clearing the debt., and/or that it's actually not as big a deal as it may sound, since we have little-to-no understanding of Subnautica's economy rates.
• You Shouldn't Know This Already: Mostly averted due to the game's open world and non-linear plot progression.
  • Code-locked doors always require the same passcode to unlock, and if you happen to know the combination from a guide or a previous playthrough, you can open them without having found the information in-game before.
  • You can investigate plot-critical locations and perform plot-critical tasks without having been given the order via radio or PDA. The story doesn't have a truly fixed linear narrative, so you can complete its objectives in almost any order, although several of them still require specific equipment to become accessible. Knowing the entrance to the Lava Lakes won't help you much without a heavily upgraded Prawn or Cyclops to actually get you there.
  • While fragments of basic gear like the Seaglide, the laser cutter, beacons and so on are semi-randomly distributed across the minor wrecks, the large ones always provide the same salvage, and important stuff like Prawn or Cyclops parts can always be found at the exact same locations. Do you know the spots? Go and get 'em at any time.

Subnautica: Below Zero

• Abandoned Laboratory: All of Alterra's facilities in Sector Zero have been abandoned, for various reasons.
  • Outpost Zero was meant to research the Architects. It was abandoned after no breakthroughs were made in part because the Architect Al-An did not want to talk to Alterra.
  • The Omega Research Lab was focused on bacteria research. Specifically, it was meant to examine strains of the Kharaa Bacterium that might have medical uses. It's implied Maida sabotaged it as a favor to Sam in order to prevent another Kharaa outbreak.
  • Lastly, there is the Phi Robotics Center and Phi Excavation Site. Contained within the Excavation Site is a frozen leviathan class organism carrying the last remnants of the Kharaa. Sam detonated a bomb at the site, accidentally killing both herself and security guard Parvan Ivanov, in an effort to halt Alterra's Kharaa reserach.
• An Alien Named "Bob": Al-An ("Alan") gives himself a designation derived from Alterra's tentative name for his species and his "seed code", producing a surprisingly mundane name. Robin Lampshades it.
  Robin: My whole life, I've been dying to meet a sapient, spacefaring alien up close, and you're telling me your name is ALAN?
  Al-An: Is it insufficient?
  Robin: No, it's fine. It's perfect.
• And the Adventure Continues: Robin and Al-An leave 4546B for the Architect homeworld, unsure of what they'll find there and if there remains any Architects at all.
• Anti-Frustration Features: There are a few new ones:
  • The new Mineral Detector tool and the improved Scanner Room can both make resource-hunting much less of a chore.
  • Oxygen Plants, which give you about thirty more seconds of air when you activate them, let Robin explore areas that Ryley would have to come back to later with a vehicle or bigger O2 tank while also being far more obvious than brain coral in the first game.
  • Dying when you have a Beacon in your inventory will automatically drop it, letting you easily get back to where you were.
  • Beacons can now be placed on land with a spike that automatically extends when you deploy one.
  • The Seatruck can be fitted with improved storage and Fabricator modules to greatly extend exploration times, similar to the Cyclops in the first game but somewhat more efficient.
  • Solar Panels now last much longer. They'll last well into the night and only shut down briefly before morning, unlike in the first game where they would shut off the minute the sun went down.
  • Instead of having to look them up constantly, you can now pin crafting recipes to the UI, allowing you to see both how much of each material you will need, how much you've collected, and how many of the item can be crafted without having to go to a fabricator or open the PDA. This helps immensely when dealing with multi-stage item crafting. This was ported back into Subnautica.
  • The Air Bladder is much improved. In the original game, its flotation when activated was barely faster than using the Seaglide to power your way to the surface, making it only useful in the very early game. Now, it's practically a rocket, allowing you to cover around 200m vertically in about 12 seconds, making it an extremely useful emergency survival tool. Not only that but now you can take the air stored in it and put 10 seconds' worth of extra air in your tank, which is useful in places like caves where the surface is inaccessible.
  • Several new structures are added to make base building more convenient. A control room can be built that can manage which rooms are drawing power, shows how much power is being generated/consumed, and helps you locate damaged sections. It also acts as a beacon, instead of having to drop one yourself. There's also the addition of large rooms, which have roughly four times the capacity of Multipurpose Rooms at the cost of requiring lithium to construct, allowing you to consolidate certain functions like power generation that would ordinarily require an entire Multipurpose Room per reactor, or just make more elaborate habitats. The latter was ported back into Subnautica.
• Awesome, but Impractical:
  • The Snowfox is essentially the land answer to the Seaglide, a Hover Bike that grants increased speed but little protection besides. Thing is, it doesn't do much to protect you from threats on land that can kill you pretty easily. It's far safer to get yourself a Prawn and march across the ice at a slow pace more or less invulnerable.
  • The Seatruck Teleportation Module and associated Tether Tool allow you teleport to the module on the Seatruck from anywhere on the map, provided the module has power. With a little creativity, this can be turned into a two-way teleportation system by exploiting how the game prioritizes which module is targeted. That said, the Tether Tool isn't powered by batteries, but by finite ion cubes, and uses a third of the cube with each jump. Unless you further exploit game mechanics to recycle the cubes, which is itself a hassle (craft an ion battery with a partially consumed cube and put it into the Recyclotron, which will output a full cube), this means it can only be used so many times.
• Composite Character: Not a character exactly, but the Seatruck is essentially a combination of the Seamoth and Cyclops; a fast, maneuverable sub in its base form that can also serve as a portable base once you've attached a few modules to it, including one that can carry your Prawn Suit.
• Crystal Landscape: The Crystal Caves and the Fabricator Caves beneath them. They are vast cave systems composed of large beryl crystals varying between purple morganites and red bixbites. There is just one big problem, it's the home of the Shadow Leviathans.
• Death World:
  • The Sparse Arctic, while not quite as dangerous, still has unique dangers that can be fatal. These include Brinicles which can freeze you if you touch them, Brinewings which can spit freezing brine at you, and Symbiotes which will relentlessly swarm you.
  • Deep Twisty Bridges as the name implies is the deepest region of the Twisty Bridges. And is the home of two creatures that want to swallow you whole. The Squidshark, and the Spikey Trap.
    • The same also applies with the Deep Lilypad Caves, with the only difference being that it is deeper and is the home of the Lily Paddler.
  • The Arctic is a vast opening within the chilly seawater. But don't worry, it doesn't have any Reapers. But, it is the home of a Chelicerate.
  • Another Chelicerate resides within the Purple Vents. Only this time, they aren't the only thing you have to worry about. It is filled with several fumaroles that will burn you if you are not careful, and is populated by a vast number of Cryptosuchuses.
  • Some how, the Tree Spires are even worse, as it is the home to not one, but two Chelicerate. And the fact this place also has both Brute Sharks and Lily Paddlers definitely doesn't help.
  • Just like the first game, this area also has an ecological dead zone bluntly called the world edge. But instead of Ghost Leviathans, you will instead be attacked by three albino chelicerates with burning yellow eyes and are covered in what appears to be rotting tissue. And somehow the white ones are twice as big as the red ones!
  • The Arctic Spires is one of the few land biomes of the game. However, it is one of the most dangerous as it is the home of the Ice Worm, a large terrestrial leviathan that digs through the ice and will devour any poor creature that gets near it. Since the creature is attracted to noise, it is best to prioritize stealth. Unless you run into a Snow Stalker that is.
  • The Crystal Caves along with the Fabricator Caverns are absolutely stunning with their vast shining beryllium crystals. But do you know what isn't stunning? The Shadow Leviathans. Each one is a Super-Persistent Predator that will relentlessly chase you down through the mineralized maze. What's worse is that the crystals are so spread out that there is barely enough space to maneuver around. Also, backing up these dark beasts are the Rock Punchers who will bust anything that gets to close to them, and the Crashfish. That's right, those explosive fish are here as well.
• Developer's Foresight: If you clear out inventory space by dropping snowballs underwater, the snowballs float up due to frozen water being more buoyant than liquid.
• Didn't Think This Through:
  • Upon discovering the Frozen Leviathan, which contains surviving samples of the Kharaa bacterium, Alterra decides to acquire some samples for study, hoping to gain numerous medical advances from the disease. The same bacterium that almost wiped out an entire alien civilization, and to which there is only one known cure that is currently being produced by exactly five living beings. The only reason things don't backfire on them is that Sam went out of her way to sabotage their efforts to research the virus.
  • As Robin lampshades at the end of the game, she never considered how she was going to get off the planet after all the effort she spent getting there.
• Disc-One Nuke: Outpost Zero has plenty of precious resources to claim if you know how to get to it. From base parts to lantern trees to PRAWN suit fragments, you're going to want to find a way to it as soon as possible. There's even a snowman that you can destroy for a Rebreather and a High Capacity O2 Tank.
• Doesn't Trust Those Guys: Robin distrusts Alterra. This informs her suspicion that something bad was going on at Sam's workplace, and her determination to find and expose Alterra's secrets.
• Eerie Arctic Research Station: There is an uneasy chill about the abandoned Alterra facilities and their inhospitable surroundings.
• Executive Ball Clicker: A sci-fi version of Newton's Cradle labelled "executive toy" that uses magnetic levitation instead of strings can be found in an executive office in one of the abandoned Alterra bases. You can also craft one yourself, but true to the trope, it's a waste of rare and important survival resources for a bauble with no real utility.
• Frigid Water Is Harmless: The temperature of the seawater is very low, but (contrary to the game's title) not below zero. In the open air, you are at risk of freezing in minutes, but the easiest way to escape the danger is to hop in the ocean, because it's generally warmer. Ironically, there's a bit of Truth in Television to this^note Nothing limits how temperatures can drop on dry land, but water will at worst get a couple degrees under 0ºC, as otherwise it wouldn't be water anymore., but it's still presumed that your All-Environment Protection Suit offers sufficient insulation and/or it's an Acceptable Break from Reality.
  • It is possible for your temperature to drop fatally low underwater — if you stay still. The activity of swimming is necessary to sustain enough body heat.
  • Vehicle thermometers register sub-zero temperatures near brinicles. If you approach these outside of vehicles, they harm you.
• Giant Enemy Crab: The Rock Puncher (basically a cow-sized mantis shrimp), and the scrapped Pygmy Crabsquid.
  • The Chelcierate is partially this. But it is based more so on shrimp.
• Guide Dang It!:
  • While the Alien Artifacts will be beaconed as soon as you are in their general area, the Alien Vessel Caches are another story. One of them will be detected similarly to the Artifacts, but the other two are in very remote areas, don't get a remark from AL-AN until you're practically on top of them, and even then don't get a beacon.
  • Maida's greenhouse. Beyond the vague directions, it's extremely difficult to find since it's well above the water and can be hard to spot with how the camera works in the Sea Truck, and with limited visibility outside of the vehicle, you're better served just looking up a video guide online.
• Harmless Freezing:
  • The Brinewing can do this to the player by spitting a jet of supercooled saltwater at them. This doesn't damage the player but makes them vulnerable to getting bit by the Brinewing, attacked by another carnivore, or drowning.
  • In contrast, hypothermia is a fatal Subversion. Letting your body temperature drop too low results in a Fade to White and death.
  • You can sometimes find fish or Pengwings that have accidentally frozen themselves to brinicles. It doesn't actually hurt them, and you can free them by breaking the brinicle with your survival knife.
  • Some of the Alterra employees express worries that the frozen Leviathan is Not Quite Dead. It's dead, but it still looks scary, so they must've been (understandably) spooked.
• Hailfire Peaks: Sector Zero, the area of 4546B that Below Zero takes place on, is an arctic ice shelf surrounding a volcanic island. It leaves frozen areas above, while there are hot thermal areas below. The distance between the hottest areas and the coldest is only a few hundred meters.
• Hollywood Density: Probably because the animation is just a palette swap on the one for cutting open doors, using the laser cutter to open passage through icebergs causes an oval slab of ice to fall down, rather than rise up through the water.
• Hostile Weather: If you are on land, the PDA may alert you to an incoming storm. The snow, hail, or fog will not harm you, but can dramatically decrease visibility and will sap your body heat much faster.
• Hover Bike: The Snowfox is useful for speeding across the ice but is incapable of crossing water.
• Inciting Incident: Samantha Ayou's death. Alterra concludes it was an accident caused by Sam's own negligence. Robin suspects they are covering something up, and goes to 4546B to find out what was really happening there.
• Lighter and Softer: Zigzagged in comparison to the original Subnautica. Below Zero's story is softer than that of the original game: the protagonist arrives on the planet by choice rather than by disastrous shipwreck; the Altera personnel were recalled, not killed by the local wildlife; the deadly bacterium is almost nowhere to be seen; the Architects are fleshed-out and come across as a far more benevolent; and even the death of Sam was a possibly-botched attempt to prevent an outbreak of the aforementioned bacterium and not Altera having her killed to cover up their actions as was initially hinted. Gameplay-wise, however, the predators, survival requirements, and hostile and isolated conditions are all still there, and the game's death animations are far more brutal and detailed if anything.
• Lily-Pad Platform: There are two lilypad biomes called the Lilypad Islands, though you can only walk on the bigger ones.
• Monster in the Ice: The Frozen Leviathan. The creature is dead and harmless. The Kharaa within it is not.
• Point of No Return: After making his new body, Al-An activates the Gate near Outpost Zero. He makes it clear that this is a one-way trip and suggests you wrap up any loose ends before completing the endgame.
• The Reveal: Several.
  • The "unknown pilot" turns out to be Margeurit Maida, who survived her fight with the Reaper Leviathan and ended up in Sector Zero.
  • Alterra found a Frozen Leviathan that still has traces of the Kharaa Bacterium. They promptly decided to study and forcibly mutate the bacterium in hope of gaining new medical breakthroughs from it.
  • The circumstances of Sam's death: she blew up the entrance to the Frozen Leviathan's cavern, accidentally killing herself and Parvan, to stop Alterra from risking another outbreak by messing with the Kharaa Bacterium. Amusingly, Alterra didn't realize she did it on purpose and wrote up the incident as "employee negligence", which is what prompted Robin to investigate in the first place.
  • Al-An was in charge of the research facility that became ground zero for the planetwide Kharaa pandemic, and the outbreak on the planet happened because he disobeyed orders and stole Sea Dragon eggs for study.
• Suddenly Voiced: Unlike Ryley, the Heroic Mime protagonist of the first game, Robin has full voice acting.
• Trash of the Titans: Marguerit Maida's seabase is filthy — the walls are coated in grime, detritus is haphazardly piled everywhere, and the kitchen is piled with weeks of dirty dishes, old food, and even a giant slab of unidentified raw meat that was hopefully intended for Preston.
• Vocal Dissonance: Some of the sound files for grunts of pain were re-used from the first game. While the main character is a woman now, when she takes damage, she sometimes sounds like she has a much deeper voice than usual.
• Warp Whistle: Scanning enough Architect technology will allow you to unlock the Seatruck Teleportation Module and Tether Tool — using the latter will warp you to the closest (powered) instance of the former, wherever it is on the map. However, both the construction and use of these are quite resource-intensive, burning through a third of an ion cube with each use.
• What Happened to the Mouse?: We never learn what's to become of Sam's cat, Potato, or who's been taking care of him in Robin's absence.
• Wintry Auroral Sky: A common sight at night. 4546B clearly has an active magnetic field.

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Until then... there's always the view.

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