"Paradox resolution in my favor. All right. Take that causality!"
Achron refers to itself as the first "Meta Time Strategy Game", i.e. it uses Time Travel as a functional game mechanic. It's possible to issue commands to units in the recent past or near future, and even send them to different times.
In additional to the standard real-time strategy user interface, players have access to the Time Window, which lets them track, switch perspective to, and order units to time travel to various points in the game timeline.
Only a small segment of the timeline is actually playable: a range that usually extends from around 6 minutes in the past up to approximately 1 minute in the future. Any events that pass beyond the past edge of the playable timeframe are finalized and cannot be changed.
'Timewaves' are regularly spawned at the event horizon between the mutable and immutable sections of the timeline. These progress up the timeline at high relative 'speed' (default settings have it at 3.1 seconds / second), carrying changes to the timeline with them. Players also act as ad-hoc timewaves; propagating any changes they observe.
A trailer can be seen here.Information on the game and ordering can be found at achrongame.com and also on Steam. There is also a helpful wiki. Additionally, there is a small demo version of the game.Not to be confused with Archon.
Adrenaline Time: Extension of bullet time: since players tend to slow down during pitch battles and then speed up after the battle to 'make up for lost time', a lot of ramping occurs.
Delayed Ripple Effect: A gameplay necessity, since if changes to the timeline were instantaneous, games would basically boil down to who sent something to the past first. Timewaves typically travel at three times the speed of time.
For Want of a Nail / In Spite of a Nail: An important part of the unit AI is to ensure player orders happen on every iteration of the timeline when reasonable (i.e. when your opponent isn't actively interfering), so that players don't get frustrated because all of their changes to the past keep undoing everything they've already ordered. Ensuring that one's strategy as a whole happens despite the interference of opponents, while also interfering with their strategies before they come to fruition, is a key component of the metagame.
Future Shadowing: Standard multiplayer game mechanic. There's also a commonly used tactic based on this called "echo scouting" where a player orders a scout to rush into the enemy's base, skips to the future to see what the scout will find, then skips back to the present and tells the scout to cancel its suicide order in the first place.
Just One Second Out of Sync: This trope occurs in a tactic called "Timewave Dodging". If a unit dies in the past, any passing timewaves will propagate its nonexistence into the present. By time traveling it right across the approaching timewave, you can prevent it from being erased from existence. Weirdly enough, you're not hiding from other time travelers; you're hiding from causality itself!
In a more straight play on the trope you can play one second in the past - you will be able to see your opponent's actions, but he won't see what you're doing until a timewave passes.
Place Beyond Time: A really strange version of it, at least. There's a section of the timeline that's hard to reach if you don't already know of its existence: "The Beach". It's a completely empty version of the map you're playing; a region in the future where causality from the present never reached. This is probably the only mechanical version of the Place Beyond Time (other video games simply create an extra, perfectly normal level and give it some backstory).
It's also completely emergent from the timeline mechanics in such a way that the creators probably didn't foresee its existence. This feature was kept in, as it has a few strategic consequences (it's possible to smuggle units across hostile borders by shunting them through the Beach).
To elaborate on the mechanics, the Beach is the very front edge of the timeline: Stuff that has scrolled onto the timeline but has not been touched by a timewave. In the space between 2 timewaves (50 real-time seconds), that area is "beyond time." After 50 real-time seconds, Reality Ensues.
Real Time with Pause: In multiplayer, no less. Bonus points for it being an actual ability as opposed to a medium mechanic.
Ripple-Effect-Proof Memory: Achrons. The game makes a strong distinction between entities that exist inside and outside time (chronals and achronals respectively). You're a general precisely because of your ability to exist outside the time stream and effect changes to it without being personally affected by it.
San Dimas Time: The way time travel works actually does a pretty good job of justifying this.
Scry vs. Scry: Future-sighting, cancelling your orders in the past, creating red herrings to confuse your opponent's future-sighting and cancelling...
Temporal Sickness: Units glow softly right after you chronoport them. They're perfectly functional, with the one exception being that they cannot chronoport again until the effect wears off. The effect has thus earned the nickname "rechronoport delay".
Time Travel Tense Trouble: The fans refer to the two orthogonal timelines as "time" (in-game time) and "metatime" (real-life time). Once you hang around the community long enough, it becomes second nature.
Timey-Wimey Ball: Averted. The rules for time travel are completely consistent both within the story and the gameplay.
Dual Mode Unit: All base class and -pod class Grekim units can enter progeneration mode. They become immobile and unarmed, but can create new units, provided other units of the same class and different type/gender are nearby.
Easy Communication: Played straight in the present and future, averted in the past: giving units commands in the past costs chronoenergy. This leads to an interesting game mechanic of assigning units commanders to create chains of command: you can minimize chronoenergy expenditure by just giving orders to commanders and letting them communicate your orders to their underlings. Also averted with the Comm Jam ability that prevents affected units and buildings from being given orders.
Enemy Exchange Program: The CESO Heavy Tank, Grekim Octoligo, and Vecgir Shin Halcyon have the ability to infect enemy units and structures with nanites. The subverted units still retain the colour and the ability to take orders from their original faction... but you can give them orders whenever you want to too. Instant spies and/or traitors!
The user interface itself helps you combat this. Whenever any of your units perform friendly fire, a message is sent to the player warning them about possible nanite infections (and letting them quickly zoom to the offending unit). This message is sent even when the player purposefully attacks his/her own units; it really doesn't know who sent those orders.
A good use of nanite infection is infecting units that can build. Just let them build turrets somewhere completely useless and watch your opponent's resources dwindle. If you do that far enough in the past, he will probably not have enough Chronoenergy to stop it.
Faction Calculus: If we equate time travel with sneakiness, then we get... Vecgir (Powerhouse) vs. CESO (Balanced) vs. Grekim (Subversive).
Fog of War: Arguably features a four dimensional variant; players need to reconnoiter the timeline for data as well as the physical map.
Instant Militia: Inverted. Resourcing is automated by "Resource Processors" and all the constructors from all the factions are military units that just happen to have the added bonus ability of being able to drop buildings (or morph into them, in the Grekim's case).
Non-Entity General: Played with. The game makes a strong distinction between chronal and achronal entities. You are the general precisely because of your achronal nature; which makes a lot of sense since battles in the game are won or lost on the basis of who can out-time-travel his/her opponents.
Averted in some campaign missions, the AI you play as downloads himself into a unit on the battlefield. If this unit is destroyed you are unable to command your forces for the period when it doesn't exist.
Also averted in Assassin Mode in multiplayer, where each player is given an 'achron' unit that they must protect or they will lose the game, as well as losing the ability to issue commands at any point where they are dead.
The game makes a distinction between the teleporters/chronoporters that you have access to and industrial ones which have much higher range and only exist in the backstory (for now). Carrying or building an industrial teleporter in the battlefield is risky, expensive and takes way too long. It's not excluded that Grekim have teleporters, just no field-ready ones. Since it's currently unknown where resources are kept, it might be either Fridge Brilliance or Fridge Logic.
They do exist in the campaign, but largely as plot points ("Get 10 units to the industrial teleporter to win") and only exists on the map as a model. Occasionally a cutscene will long-range teleport units out (or the game will spawn units on one, simulating a long-range teleport in), but they don't exist as a usable building of any kind.
Shoot the Medic First: The CESO Blackbird can repair units at speeds so fast it can greatly affect the outcome of a battle. This leads to it attracting a lot of focused fire.
The auto-attack algorithms have now been tweaked so that units prioritize targeting medics like the Blackbird or MFB first! Heck, the trope is even referenced by link within the manual on the Achron Wiki.
Tactical Rock-Paper-Scissors: It is unclear, but this seems mostly averted. Units have at most 2 weapons, generally one for ground targets and one for air targets. Apart from this, the damage is the same against all targets. For Air and Ground units, though, the trope is in full force (some units are significantly stronger against one or another)
Tech Tree: Each faction has a very small, very flat tech tree (usually amounting to around six upgrades or so) and they are explained away as "improving infrastructure" (as opposed to "research"). The interesting bit is the way this interacts with the time travel mechanics: It's possible to arm your units with weaponry from the future, or reinforce your army with units you can't technically build yet.
Teleporters and Transporters: It is fantastically easy to teleport in this game. The demo tutorials teach you cross-map teleportation before they tell you about control groups. One race can even upgrade units to teleport without a gate, but it isn't as long range. The same race even has a superweapon, a missile, that can teleport into the enemy's base.
Teleport Spam: Vecgir units tend to do this once they've been upgraded, which occurs automatically once you get Gate Tech.
You Require More Vespene Gas: All of the races require 'L-Crystal' and 'Q-Plasma', which are found in supply crates left scattered across the maps. Word of God is that L-Crystals are basically raw materials for the Nanomachines to build useful things out of, whereas Q-Plasma is used to create the more exotic types of Phlebotinum. CESO (the humans) also has a resource called 'Reserves' which ostensibly looks like Population (its icon is a small stick-figure person, and all units have a small integer cost), but it doesn't act as a unit cap; Importers continuously generate more and more Reserves over time... its closer to a cap on the number of units you can generate per unit time. The Vecgir also have a resource called 'Power' which is provided by most buildings, used by vehicles, and must be above 0 for unit energy pools to recharge.
Worker Unit: Averted. Each race has units that can build structures, but they are all combatant units who happen to build structures, not workers that happen to have a gun. The Vecgir don't even use mobile units for most of their structures, building them instead from existing structures.
Zerg Rush: the Grekim can do this the most easily, thanks to progeneration. May occur with all species in certain situations.
A.I. Is a Crapshoot: Largely Averted. A sentient, economy-controlling AI did participate in a massive colonial revolt, but the reason was actually programmed in: The AI was designed to do whatever it took to avoid long-term macroeconomic collapse. After this event no further AI of the same type were legally allowed to be created. However, the human special ops division did create some illegally, and the player character is the sentient, economy-controlling revolutionary AI in question.
Aliens Are Bastards: The only explanation humanity can find for the destruction of a number of their colonies... for now. It's actually because humanity's foray into time travel, discovered right as the Grekim attack, is muddying up the timeline and the Grekim do not want that.
Arc Number: The AI Echo is fond of the number '76,013', which is ultimately revealed to be the number of Stable Time Loop iterations so far.
Badass Boast: Lachesis, having already managed to survive being destroyed in the backstory for inciting a colonial revolt, points out that the Stable Time Loop between him and the Coremind is just another trap, which he will be able to escape.
Cool Gate: Teleporters, Chronoporters (that facilitate mass teleportation and mass time travel respectively) and Slipgates (that facilitate both) look like cool spinning stargates. Which is a bit unnecessary since no unit actually walks through them.
Decoy Protagonist: At first it seems like Captain Holloway is the protagonist, with Tyr (the player character) being his Voice with an Internet Connection support, but then it turns out that Tyr is the actual protagonist at the end of the first campaign.
The Dragon: Guardian, a Grekim Keeper (essentially senior officer, but not leader) is trying to rebuild the Coremind to re-unify the Grekim and destroy humanity in 10000BC. Transforms into The Starscream once he realizes that he is an individual and he would end up losing that, not to mention that he is the only surviving Grekim leader at his era.
Gameplay and Story Segregation: The intention is to avert this. Speaking to the devs reveals that the story is being carefully edited to avoid plot holes or softness with respect to the in-game mechanics of time-travel, among other things. However, It is possible something might slip through.
"Groundhog Day" Loop: Or rather Groundhog 13000 year loop. Echo has been dug up, used to assist Lachesis and the PnC, chronoported back 13000 years, assists the Grekim in learning enough about Lachesis to enslave him. Then gets rebuilt as Jormun, leads then sabotages the Human/Vecgir ground war against the Grekim, and ultimately stops Lachesis from ultimately destroying the Coremind. This has happened 76,013 times at the end of the main game, which means Echo has been around for at least 988 million subjective years. It seems to be enjoying itself quite a lot watching the different iterations go by, though.
Hive Mind: The Grekim and initially the Vecgir are controlled by the Coremind, essentially a giant distributed AI that uses the Grekim Arcticuses as nodes, and which connects to all Grekim and initially Vecgir via neural radio transceivers.
Portal Network: Occurs in the backstory as the human transport backbone. Also occurs in-game to a fashion if you're a fan of the 'slingshot' structure, which can shunt any units that approach it automatically to a point in space anywhere in a wide radius around it. If you build enough slingshots, you can chain them into teleport-bridges that can shunt your forces between all your bases.
Portal Slam: The focus of the story will be on a group of survivors of the invasion left behind after the aliens destroy the Cool Gate which connects them to the humans' Portal Network.
Precursors: The Remnant system (where the game largely takes place) was named for the ancient remains of alien outposts that can be found on planets throughout the system. The humans most advanced technology is derived from technology found in the ruins.
Rooftop Confrontation: The final level takes place on the roof of the complex where Guardian has been trying to set up a communications relay to contact the Coremind. It's just you, him, and your armies. Your only goal is to kill him
Stable Time Loop: In the end, Lachesis is able to defeat Guardian and almost defeat the Coremind 13,000 years before the events at the start. However, some of its component Arcticuses were squirreled away by Guardian, which allows it to recover. It rebuilds itself in Lachesis's image and goes to attack Humanity, thus getting us to the events at the start of the game. Echo/Jormun has been enjoying watching this play out the last 76,013 times.
This Stable Time Loop also extends to the Vecgir technology used to jumpstart discovery of teleportation and chronoportation technology. The ruins discovered were actually the bases built by the Vecgir and Humans after the 13,000 year chronoport, thus the discovery of these technologies as they were discovered is dependent entirely on the loop. However, it is highly likely these technologies were originally discovered by Humanity independent of any ruins, but the first iteration of the Grekim invasion and humanity's counter-attack would have caused the loop in the first place.
Combined with the Transhuman Aliens entry about Humanity likely ultimately becoming Vecgir (probably Grekim prisoners from the first few iterations), the existence of the Vecgir, or at least at this era, is an Ontological Paradox. This also explains why all three races use the same resources, as the tech is ultimately either made or stolen from Humanity.
Starfish Aliens: In addition to being essentially sentient, technological, time-traveling space squid, the Grekim have 3 genders, Octo, Sepi, and Pharo, which double as unit types. Any 2 genders can reproduce, or progenerate, together to produce a member of the 3rd gender, either of the same unit class or of the next class better.
Nanomachines One of the main resources in Achron is called Liquid Crystals (LC for short) and is made of a mix of common atoms and nanobots in a liquid-crystal framework. When you order a unit to construct a building the unit drops a tiny transponder seed which signals local teleportation infrastructure to teleport the right quantity of LC to that location. The nanobots in the LC then assemble the building using the atoms contained within it. When you build a unit the LC is teleported into the factory where it assembles into the units gear in a similar way (and the pilot is supplied separately).
Tomato in the Mirror: Twice. First, the player finds out that the character they've been playing (Tyr) is in fact Lachesis, the same AI that caused the rebellion mentioned in the backstory. Second, at the end, Lachesis realizes that the Coremind it's been fighting all this time is, to a degree, itself, or at least rebuilt after its image.
Turned Against Their Masters: Jormun/Echo turns against humanity in the end, causing Lachesis's ground war on Drasil to collapse and leading to his eventual defeat
Transhuman Aliens: It is not stated outright, but can be inferred that the Vecgir are in fact the decendants of humanity that have been enslaved and modified by the Coremind in a loop that has been going on for millions of meta-years.
While the current game generally involves around four players fighting across seven minutes of time, this is simply a computational constraint of modern hardware. The devs have future-proofed the Resequence Engine by making it scalable: it can theoretically support up to fifteen players fighting across a two-week long active timeline populated with thousands of timewaves.
Gambit Pileup: The obvious result of two enemies with time travel technology trying to turn the tide of the same battle.
Meaningful Name: Achron is derived from Greek — the "a-" prefix means "not" or "without", and "chron" is from "chronos", meaning time. In-story, an Achron is free from causality, and therefore outside of time.
No Body Left Behind: Destroyed units immediately disintegrate in a pretty storm of polygons. This is mostly to make the game kid-friendly.
Tron Lines: Units are depicted as mostly-translucent silhouettes with edges that glow with the unit's team colour. This is an interface concession to make your troops easier to spot: according to the setting, all three of the species use advanced camouflage on their military units, making them near invisible.