These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The Engi theme. On the sector map, it is an extremely sedate (if tense) piece, one which is difficult to imagine overlaying anything over it to produce a battle theme. Yet like the other themes of the Variable Mix, it does just that. That alone is grounds for awesome, but the Engi battle theme is also one of the best in the game.
Last Stand is that kind of piece to get you pumped to go out and rip that Flagship to shreds.
Applies for Federation. Apparently it was cut because it did this too well
It's a Cut Song, but Horror does its goal of setting a creepy atmosphere very well. Toowell, as Ben Prunty mentions in the liner notes.
Breather Level: Due to the Engi being peaceful and generally non-aggressive by nature, Engi-controlled sectors tend to be easier to clear than most other kinds of sectors.
Demonic Spiders: Just about every ship in the game has a certain strategy it's just not cut out to handle, at least until you somehow acquire the hardware and/or crew to make up for starting deficiencies. For instance:
Boarding parties, especially Mantis boarders or large 4-man groups, for ships that start off with small and/or combat-incompetent crews, which include:
Both Engi cruisers (Type A has two Engis and a Human, Type B has just a single Engi), seeing as Engis do half-damage in combat. The Type A, however, has a Medbot Dispersal augment to help its crew in combat, and the Type B can be run almost completely depressurized (outside of the cockpit) once you get blast doors, and until you get extra crew, as its "crew" of internal drones don't need oxygen.
Both Zoltan cruisers. The Zoltans are the most fragile race and moving them around results in ship systems losing or redistributing power, resulting in weapons getting canceled, cloaks getting deactivated, etc. Their Zoltan Shield augment can prevent enemy ships from using their teleporters or launching boarding drones while it's active, but the Advanced Edition introduces a special augment that allows enemies (and the player) to get past it, and several random events involve its use.
Both Slug cruisers. It's not quite as bad for them since they can telepathically track the enemy boarders, and the Type A helps its two-Slug starting crew by being pre-equipped with blast doors. The Type B though has no starting medbay, and it depends on its Healing Bursts to keep its three-Slug crew alive, so if weapon systems go offline or you run out of missiles, you have no way to heal your crew.
All three Stealth cruisers. With no shields, evasion and cloaking are their main form of defense, and they need their systems to be manned more than any other ship. The Type A, though, has a crew of three Humans, while the Type B has two Humans and a Zoltan with only a two-square medbay. Boarding parties in your cockpit are bad for any ship, but are worse for the Stealth ships because you lose evasion and can take hits even when cloaked. The Type C gets a shield overcharger that creates a Zoltan shield, but it's only 1 bar of shield, it takes loads of scrap to upgrade the power system, and then to buy a shield.
To a lesser extent, boarders are also problems early on for the Kestrel A, the starting ship, which also has 3 Humans, and the Federation Cruiser B, which has a Human, a Slug, and a Zoltan.
The Rock B has no external doors, and the crew of four Rockmen are sturdy but very, very slow. If enemies board you, you cannot simply vent the room they're in, you have to chase them around with your crew. And your crew is so slow that any boarders will have probably destroyed a system or two by the time you finally catch up to them.
Attack drones and beam drones for any ship that doesn't have a proper shield system, seeing as the drones have higher damage-per-second than regular weapons at the cost of burst damage capability, and are hence particularly lethal against unshielded targets. This includes all 3 of the Stealth cruisers, and to a lesser extent the Type B Zoltan cruiser. The Stealth ships cannot conveniently cloak away from the almost continuous drone fire like they can with ship-to-ship weaponry volleys (not that the Stealth C can do that anyway), so hull damage becomes inevitable. With the Stealth A (Nesasio), you can still go under cloak early and try to take out the enemy drone control with your first volley. But with the Stealth B, you have to wait and suffer, and if your weapon systems are hit, your power-hungry Glaive Beam goes offline and your only option is to try and run. The Stealth C has it that much worse, as its only protection from drones is the fairly unreliable Anti-Drone and its slow-charging Shield Overcharger, as it lacks a cloak in spite of being a Stealth cruiser. The Zoltan B has temporary protection with its Zoltan shield but drones tend to tear through it fairly rapidly, but like a cloak, this still buys you some time to charge your weapons and try to disable the enemy's drone control. The Zoltan B also has it easier since it can acquire regular shields earlier than the Stealth cruisers can.
Zoltan Shielded enemy ships for any ship whose direct-damage offensive capability is either completely dependent on missiles (Rock A, Slug B), or just flat out non-existent (Mantis B, Unidentified B). A Zoltan shield takes five damage to knock offline, which is the equivalent of three missiles. That's basically one whole dead ship in the early sectors. And ships that start with no weapons at all have no option except to run, since the shield blocks out teleporters and boarding drones (Advanced Edition adds an augment that can bypass it, but getting that is hit or miss). Furthermore, the Zoltan Shield takes at least one round of combat to knock out, three if you're unlucky. For the Stealth B, which depends on One-Hit Kill tactics with its Glaive Beam to prevent (most) damage in the early game, that extra round is an eternity of vulnerability which can easily cost you the game.
Ion Storms, a randomly occurring environmental effect in Nebula nodes. Running into one cuts your reactor output in half and depowers systems at random accordingly. This works on your enemy, too, but they can generally manage greater reactor output than you can. When you have to juggle power between your weapons, shields, engines, and life support, you can expect the enemy waiting for you to put some big holes in your hull before you make it out of there. Fortunately, having the Long-Range Scanners augment you can see the storms from afar and avoid them accordingly.
Boarding drones. They're essentially Rockmen boarders but with the attack power of a Mantis and an immunity to suffocation. They pass through shields and cause a hull breach in the section they impact, making it that much harder to kill them if they're attacking a system. Oh, and if you manage to kill one, the enemy will just send another, which will put another breach into your ship, unless you take out their drone control first or they run out of drone parts. If you get hit by one, hope it doesn't land anywhere vital and destroy the enemy's drone control before it causes too much damage. While they can be intercepted by defense drones, they're small, fly fast, and can be launched faster than missiles, and have a better chance of getting by as a result. Zoltan Shields and cloaking can buy you some time to try and take out enemy drone control, if you have them, and Slug ships can automatically repair breaches, making them slightly less hazardous. Advanced Edition implemented a cooldown on all destroyed drones that nerfs this significantly; now drones take about as long to recharge as an average missile, meaning that while it will take far longer to force the enemy to run out of them, neither can they spam them at speeds greater than you can counter. Sadly, the hacking system did not get this treatment.
Most of the time, Rebel AI-controlled Auto-Scouts and Auto-Assaults are Goddamned Bats. However, ships that lack direct damage weapons will find themselves largely incapable of doing anything about these ships. The Mantis B can defeat Auto-Scouts by launching a Boarding Drone at them and letting it destroy and re-destroy systems while the Auto-Scout auto-repairs them, but this doesn't work against Auto-Assaults because they're compartmentalized and hence prevent the Boarding Drone from moving around within them, requiring a very tedious and specialized method to destroy them without weapons. The Unidentified Cruiser Type B can't destroy them either until you find some regular weapons. And, to provide a challenge for any and all ships, sometimes in the late-game you can run into really dangerous Auto-Assaults, packing defense or anti-ship drones, cloaks, full batteries of four weapons, stupidly high evasion, and (rarely) up to five layers of shields. And since they're automated and depressurized, they can't be damaged by fire and have no crew that can be eliminated, so you're in for a long hard slog to try and bring them down.
If you're in a Slug nebula, then expect to run into many events where a Slug ship hacks your oxygen/medbay/doors/engines/various other systems, and then exploits your newfound weakness. If you haven't upgraded your systems enough to get a blue option, then you're in for a world of pain. Particularly nightmarish are the ones where they hit your oxygen, since that essentially puts you on a strict timer to either kill the ship or bail.
Any enemy ship with a medbay is this for the Mantis B, a boarding-oriented ship that doesn't start with any weapons. Enemy crew will simply retreat to the medbay at low health, and fighting in the medbay is pointless since the enemy can simply heal faster than you can damage them. Unless you've managed to pick weapons capable of hitting the medbay, your only hope is to get the crew to retreat to the medbay then cause damage to the shields (easier said than done, even with a Boarding Drone to create a distraction), since the AI prioritizes the shields over anything else, allowing you to take out the medbay. The Crystal B ship is also boarding-oriented with no weapons, but at least Crystals can beam into the medbay then lock it down until it's offline.
The ships in the Crystal Home Sector. They tend to show up with full arsenals of crystal weapons, which ignore one layer of shielding. Even worse, Crystals are very tough to kill, having boosted health and being resistant to suffocation. They can easily put a serious crimp in your plans to complete That One Sidequest.
Enemies with hacking capability can be this, depending on your loadout and where it hits (randomly assigned thanks to Artificial Stupidity). The worst is when it hits the weapons system of a player that relies on long-charge-time weapons (which can shut down your entire offense and make the encounter Unwinnable if you have no other way of destroying or disrupting the enemy hacking system), a non-upgraded O2 system (which drains oxygen far faster than a mere hull breach and can easily mean death for your entire crew if you can't destroy or disrupt the enemy hacking system or jump away fast enough), or a medbay when the enemy also has boarders attacking you.
Teleportation, so long as you have even a moderately competent boarding party, quickly builds up scrap thanks to the increased rewards from boarding, gives some of the best victory options, and requires minimal to no assistance from your ship unless they have a medbay/clone bay. Your ship only needs to be able to resist the enemy's attacks until the crew is dead. It's more difficult to use against automated ships, but it's still so powerful that winning without a teleporter and boarding party verges on a Self-Imposed Challenge.
The Weapon Pre-Igniter plus any of a half-dozen powerful weapons with a long charge time as their Necessary Drawback. Being able to open fire the moment a fight starts typically lets you crush any opponent who isn't completely immune to your arsenal. Even the final boss is a lot easier to beat thanks to being able to shut down some its more powerful abilities on the spot. There's an achievement for destroying an opponent outright with this ability.
The Rock Cruiser Type B, "Shivan". Its Heavy Pierce Laser can dominate early sectors before the enemies get over one layer of shielding and stays useful through the endgame. It charges fairly fast, ignores one layer of shielding, does as much damage as an Artemis missile without using ammo or being vulnerable Defense Drones. Once you find a teleporter, the combination of a fireproof Rockman boarding party and Fire Bombs becomes even more powerful.
The Crystal people. Their ability to lock down a room, preventing anyone from entering or leaving makes whoever you are facing in the room outnumbered, outgunned and unable to escape, ensuring a certain death. Combined with their extra HP and tolerable speed, and you have the ultimate boarding crew. Their Type B ship takes this even further, with a four-capacity teleporter right next to a medbay, and you start with three crew. Their Type A ship is no slouch, either, possessing weapons that bypass one layer of shielding and don't require ammo. Their Game Breaker property is heavily justified though, as the way to unlock them in vanilla FTL requires a horrendous amount of luck.
The Mantis Cruiser Type B "Basilisk", with its starting 4-man teleporter, boarding drone and level 2 shields. It doesn't come with weapons, but you do not need them. There are only two types of ship it cannot beat outright, one of which is easily corrected once you've got some scrap to upgrade your teleporter one level. Almost every encounter can be won simply by beaming over your entire crew to kill off the opposition while your shields soak up any damage they can do. This also gains a lot more scrap than blowing ships up, making it much easier to improve the ship. For AI ships, you can use your boarding drone to destroy systems slowly (AI-Scout) or a combination of the level 2 teleport and drone (AI-Assault). With all that extra scrap, you can easily buy weapons to disable ships you can't kill by boarding. By far, this ship is the easiest one to get to the endgame with because it affords a considerable early game advantage. Its only disadvantage is Zoltan ships, which can't be breached with the teleporter while their shield is up (unless the Random Number God blesses you with a special bypass augment).
Breach Bomb II, which tends to wreck entire ships in one well-placed burst if it hits. Because it does damage to crew members and opens holes in the ship, this can be used over and over to disable most any ship save for Slug ships without destroying it. This even works on the Flagship; repeatedly applying the Breach Bomb to the medbay in the first stage can lead to the entire crew dying painfully, leaving it open for a boarding party to disable during the other stages. Finally, AI drones and the Flagship's last-resort AI don't repair breaches, and breaches in system rooms need to be repaired before any system damage can be repaired, so any system damage in a breached room will never get repaired, leaving them permanently disabled (unless you jump away and then come back later).
Ion Blast II combined with one or more Ion Blast I. It only takes a few quick salvos to take down even level 4 shields, after which you can keep two or more systems more-or-less constantly disabled, then just relax and take your time finishing off the enemy. Especially good in combination with beam weapons, or with teleported crew.
It's also the best weapon for leveling up your crew's Weapons skill.
Mk. II Attack Drones. While they cost the normally excessive 4 power to use, they fire much faster than a Mk. I, take only half the space to use, and, if you can manage to get your hands on two of them, Can basically defeat the final boss on their own
Advanced Edition adds the hacking and mind control subsystems, which completely unbalance the game once you get them. Forget needing a teleporter, just launch a hacking drone at the oxygen and suffocate the ship. Use mind control to make the crew kill each other. The downside, of course, is that it's almost as easy for the enemy to do this to you with the same.
The Lanius B Cruiser gives you a clonebay, mind control, a teleporter, advanced version of the Flak Mk 1 (only cost 1 energy to operate and has lower recharge time to boot) and two Lanius. Who drain oxygen from rooms. If you can't be hurt by the enemy, then it's triviality to use the flak to destroy the enemy oxygen room, teleport the Lanius in, fight for however long it takes to drain the oxygen out of that room, followed by the rest of the ship soon enough.
Also from Advanced Edition, the Vulcan Cannon. It's extremely rare, starts slow, and takes 4 power, but it is the only weapon you will need. The time between its shots drops by two seconds with each firing, so eventually it fires 1 shot per second; the fastest enemy shields will recharge is 1.5 seconds. Battles are reduced to setting the Vulcan to autofire on the shields and breaking it apart, then destroying enemy systems at your leisure and occasionally reminding the enemy crew the futility of repairing the shield with another shot. Not even several misses in a row can stop the onslaught for more than a brief moment. Pairing it up with a Glaive Beam (difficult, considering that arming the two together will take eight bars of power, the maximum your weapons system is allowed to have) will require a small fortune in scrap and either luck or starting with the Stealth Cruiser B, but will give you an unlimited ammo weapons set that will melt anything that you point it at, provided you can survive long enough for the Vulcan to spin up and the Glaive to charge.
Genius Bonus: A couple of the ship names qualify. Ariolimax is the genus for banana slugs, named for their yellow coloration. The corresponding ship palette is also a bright yellow color. Likewise, the Nesasio is named after a genus of owl, a kind of bird known for being silent and stealthy.
AI Controlled Scouts when using the Mantis Cruiser B. No weapons, you have to send over a boarding drone to very slowly blow up each of the ships systems, wait until they repair a few times, and then finally the drone will blow up the ship for measly scrap, often less than 10 value on Normal.
Auto-Scouts also have the nasty habit of trying to FTL escape to inform the Rebels of your position, making the Rebel army advance faster if they succeed in doing so. In an amusing contradiction, however, if you jump away first, this doesn't happen.
Auto-Scouts in later sectors tend to have stupidly high evasion. Coupled with multiple layers of shielding, firing a volley of 8 shots and still failing to land a shot is not unheard of. This, like the above problem, can be solved with the use of the Hacking system targeted at their engines, but it can be seen as a waste of a drone part to take out an AI ship.
Slugs in general, with their system-disabling shenanigans. Add in that they live in nebulas, which people already tend to avoid for their sensor-disabling annoyances and the aforementioned plasma storms, and you get one really annoying race to deal with.
Ion weapons, especially either Ion Blasts or Ion Bombs.
Ion Intruder drones in the Advanced Edition combine ion weapons with boarding drones. While not as dangerous as boarding drones due to their lower durability and inability to cause direct damage, they absolutely love to stun vital crew members or disable important systems at the worst possible moments.
Cloak tends to prolong most battles it's in. Usually, the only dangerous enemy that has cloak is the Flagship. Most of the other times, all it does is waste your time.
Zoltan ships with Zoltan Shields, if you do have weapons, primarily due to the extra time needed to eat through them.
Good Bad Bugs: The new features of Advanced Edition have some possibly unintended effects on achievements, making them far easier to unlock.
"The guns... They've stopped" requires using the Engi ship to simultaneously cause ion disruption to four different systems. Normally this would require at least two ion weapons. However, with the addition of pulsar nodes, the ion burst can potentially knock out enough systems to let you earn the achievement with only one ion weapon.
"Avast, ye scurvy dogs!" requires you to kill five enemy crew using the Mantis ship without taking hull damage or having any of your own crew die. While that many crew don't become common until late in the game, cloned enemy crew count toward the total, making it much easier to get the achievement in an early sector if you can find one with a Cloning Bay.
Mind Controlled crewmembers are treated as AI-controlled members of the opposing crew. A controlled enemy is treated as one of your own crew, and as such you can use a Teleporter to "return" them to your ship... where they are easy pickings for your crew once the Mind Control wears off.
The fact that many elements of the game are random does not sit well with some players. Case in point: In one run, you may end up finding four Burst Laser II's, allowing you to cheese the Final Boss with 12-shot laser spam. In another run, you may be stuck with default weaponry or at the least ineffective weapons at stores that prevent you from damaging the flagship at all unless you also invest in a teleporter.
The occasions where you have to choose text options with no idea if they'll wind up helping you or hurting you. To give one example, you might have to choose whether to let a seemingly insane person on board. You will either lose a crewmate or gain the one you let on board as a crewmate, with nothing indicating which outcome will play out. Thankfully, there are occasionally options highlighted in blue which help you no matter what.
One particularly crazy one involves using absolutely no oxygen on your ship at all. You'd think everyone would quickly die from asphyxiation, but apparently a level 2 Medbay completely nullifies the damage taken from asphyxiation. It's still ridiculously difficult, since the Medbay is only so big, and you need someone at the helm to jump the ship from point to point. It's been done, however crazy it sounds.
Some people think that Engi Cruiser B or Stealth Cruiser B are also "hard-mode" ships. Engi B has a single crewman, no sensors, and has drones take care of boarders and ship repair; one could take it a step further and go for a Solo-Character Run, never hiring a single new crew member (and if any are picked up for free, kill them by asphyxiation). Stealth B has no shields and starts with only one weapon: the incredibly slow-charging but powerful Glaive Beam.
Ancestry, which requires you to go through That One Sidequest in the Rock Cruiser. That said the Rock Cruiser has blue options that make it slightly easier to complete. If you intend to do it in the Type A, get non-missile weapons as soon as possible (see Demonic Spiders above). If you intend to use the Type B, you need to complete two other hard (but still much-easier-than-this-one) achievements in the Type A to gain access to it - which involved destroying an enemy ship which has a defense drone using only missiles (alright, you start with only missiles, but defense drones are... designed to block them, and ships that field them often have the crew or repair drones to keep their drone control online), and killing an enemy crew in a room which is on fire (which is hard because you need to set a room on fire, then board it and kill an enemy crew member there - and the enemy crew members are programmed to flee from burning rooms if they can).
Missiles in general are much hated by just about everyone without a defense drone. It's not that they're powerful (early on they do one or two damage a pop), it's that they pass through shields. Worse still, they charge fast enough that you can pretty much guarantee the enemy will fire at least one before you stop them. Just to be clear, there's a good 75% chance that any given enemy, especially in the early sectors which only get a limited loadout to choose from, will have a missile launcher. Later in the game, enemies can field larger missiles that do as much as four damage per hit, but they mercifully take longer to charge and you'll probably have a defense drone by then, as well as high evasion and possibly a cloaking system to help avoid them.
The flagship's triple missile launcher is notorious for this reason. At best, a defense drone of any make can take down two missiles, and while you can cloak to dodge them, this only works every other time due to the longer cloak recharge. Unless you're fast with your teleporter, odds are a missile is going to connect. On the final stage, it's practically a guarantee since the Zoltan shield takes so long to get through.
The hacking and mind control subsystems in Advanced Edition. The hacking drone can be fired at any system and reverses the function of the system it hits (oxygen drains, medbay damages, weapons and shields lose charge, dodge is shut off). Not only that, the room it hits is locked down and has to be broken into. It also doesn't suffer from the drone-cooldown added to prevent drone-spam, so your enemy is going to fire it like it's a machine gun until they hit you. The mind control system co-opts one of your crewmembers and causes them to turn against you, usually attacking whoever or whatever is in the room with them. This can potentially shut off your ability to dodge or damage critical systems. In both cases, you can only hope you can knock the system offline before it does too much damage. On the plus side, these two are every bit as gamebreaking under your control.
The flagship's first power surge, the drone swarm, is possibly the single most damaging attack in the game. If your shields go down for even a second, you WILL be feeling the pain. It's not an exaggeration to state that if this pierces your defenses and takes out a vital system (like shields), you will probably lose. It also has a tendency to sync with the triple heavy lasers connecting with your shields or the triple Leto missiles firing. You'd better pray that their Halberd Beam isn't also up.
The flagship's bigger attacks practically make it mandatory to have an evasion stat over 50% (and/or a cloaking device) which you can never, ever let go offline, because you will die if your evasion is turned off. You also better hope the boarding drones in the second stage land somewhere other than your cockpit, or that your defense drone can shoot them down repeatedly until the flagship's supply runs out.
The flagship got even cheaper with Advanced Edition. Now the first round has the hacking subsystem which needs to be shot down by a defense drone, and the flagship shoots them really fast. Worse, its missiles are almost guaranteed to distract your defense drone long enough to let the hacking drone hit you, which can be deadly depending on what it hits (if it hits weapons, shields, or engines/pilot, jump away from the battle as soon as possible; you've basically lost otherwise). The third round gets the mind control system hidden behind the massive Zoltan shield, which means you'll have a crewmember running around under enemy control for a significant period.
Advanced Edition adds an event where a Rebel AI ship hacks your shield system, reducing it by a point, and this can happen in the first sector. In other words, you have no shields for that battle. Worse, this ship usually gets a combat drone as a package deal, meaning you have to spend the next ten or so seconds getting smacked around by a drone while praying your weapons get enough time to charge. It's not an exaggeration to say that you can die by no fault of your own thanks to this event, because certain ships simply have no way to counter it.
Shieldless ships. Only four ships don't start with laser and beam-repelling shield systems and while they have alternatives (a cloaking system in two cases, a special single-use shield in the third, and a special drone that periodically charges up one layer of a that same normally single use shield) they can be rapidly picked apart by anything with a beam drone (attack drones fire constantly for low damage which shields would normally absorb, but which adds up, and beams can't be dodged).
The Repair Arm augment. Any moderately savvy player knows to never buy this piece of garbage, since it steals 15% of your scrap to do something that is both cheaper at a store and which should at best be occasionally necessary if you know what you're doing. What makes it fit this trope is that you can be "awarded" the augment as part of a random event, forcing you to rush to a store to dump the thing. Depending on how far along you are, this can either be a small scrap gain, or a small to moderate scrap loss.
That One Level: Primarily dependent on your ship and equipment. Several come to mind:
Nebula sectors for ships that do not have Long-Range Scanners, due to Ion Storms.
Slug sectors, which are a subset of nebula sectors and often have events where your ship's systems get disabled, or reduced in effectiveness if you had the foresight to upgrade them.
Ships that do not start with weapons should avoid Zoltan sectors until they get a few, as Zoltan Shields block teleportation (assuming they didn't buy the Zoltan shield bybass sugment).
Rebel sectors are generally difficult for all ships due to the onslaught of Rebel ships, which include drones that can't be easily destroyed by boarding methods and often have high evasion. In Advanced Edition, Rebel nodes come with Anti-Ship Batteries, making getting caught by the fleet even more dangerous.
The "Unidentified Cruiser" is a Game Breaker for a reason. Many players take dozens of attempts before they get a run that gets the very specific, luck-based order of sectors that allows the sidequest to be finished.
To a lesser extent, unlocking the Rock Cruiser Type B, which requires completing two out of three Rock Cruiser achievements:
The Ancestry achievement is the same thing as hunting down the Crystal sector, minus acquiring the Crystal Cruiser.
At the least, the Defense Drones achievement is simple—just find a Rebel Rigger with a Defense Drone and then use missileAlpha Strikes to prevent the Defense Drone from being able to shoot both missiles.
The "Is it warm in here?" achievement requires killing a crew member of an enemy ship in a burning room, which is not easy because this requires a Teleporter and a way to start fires. Most weapons only have a low chance at best, and it's not uncommon to never find the Fire Beam or Fire Bomb, and even then Fire Bombs use missiles and can miss, while the Fire Beam requires that the enemy ship's shields be down first. Oh, and enemy crews retreat from burning rooms at low health, requiring you to time your attacks correctly so they get their last points of health beaten down before they can escape the room. And finally, the crew member must die from one of your hits; if the fire whittles them down to 0 HP, it doesn't count! You can guarantee this achievement by getting to the Rebel Flagship with a Fire Bomb in tow and using it on one of the weapon rooms, but it still takes a bit of a while to get there. Advanced Edition makes this somewhat easier if you have the hacking module, as that can be used to lock down a room and then kill the occupant.
The Slug B ship, The Stormwalker, which is a boarding-oriented ship. The catch? It has no starting medbay, and all three of its starting crew are Slugs, which are average boarders at best. The idea is to use Healing Bursts to recover your Slugs so they can keep fighting, but Healing Bursts use missiles, happen to be your only means of recovery (which means post-battle recovery will consist of wasting another missile), if your Burst misses you will have to beam your boarding team out, and if your missiles run out, you're screwed. Early game tactics involve making a mad dash for the nearest store so you can purchase a Medbay, which costs 60 scrap.
The Engi B ship, the Vortex, starts with one Engi crew member, and its weapons consist of a Heavy Ion and a Heavy Laser. You can depressurize every room except the cockpit to stop fires and hold off boarders (especially in conjunction with your Anti-Personnel Drone), but if you get boarded in the cockpit (especially if the boarders happen to be Mantis), you are in a lot of trouble, as Engis have halved combat damage and leaving the cockpit will drop your evasion to 0% unless you have the cockpit upgraded to have an autopilot, and even then your evasion will remain nearly nonexistent unless your engines are maxed out (though the Advanced Edition improved the autopilot). As for the weapons, the Heavy Ion takes a long time to charge, and if it misses, you won't be able to use your Heavy Laser on anything unless you're up against an unshielded Auto-Scout or are in an asteroid field with a one-shield ship. The slow recharge rate of the Heavy Ion also means that if you don't find another gun to help supplement it, you're basically dead when you start facing enemies with 2 shield blocks, since even with maxed out gunnery skill, the ion damage on shield will dissipate before another ion shot hits. It also starts out without sensors and, unlike the other ships in this category, doesn't even have a real late-game advantage in form of a great weapon or special ship-property.
The Stealth B ship, DA-SR 12. Like the Stealth A ship, it starts with a cloaking device and the shield system must be purchased separately for 150 scrap. Its main differences are that it has only level 2 engines instead of level 4, has level 2 cloaking, and its only weapon is the Glaive Beam, a beam that does 3 damage per room, but takes 25 seconds to charge (about 23 if you have a zero-level gunner) and uses 4 bars of energy. Even the Federation Cruisers' Artillery Beam fires faster when maxed out. If your weapons and/or your cloaking get hit in the early game, your best choice is simply to restart.
The Stealth C ship, Simo-H. Unlike its sister ships, it lacks a cloaking device, instead opting for a special version of the Shield Overcharger that takes less power and charges up slightly more rapidly, an Anti-Drone, and a third slot for drones, being the only non-Engi cruiser with that many slots for drones. However, the Shield Overcharger+ only puts out 1 bar of Super-shielding, the ships that only have one weapon are few and far between, and you can't keep both the Shield Overcharger and the Anti-Drone powered at the same time without spending precious scrap to upgrade the Drone Control and your reactor, and you obviously need that to buy a set of Shields for the ship. It can be powerful later on, but the other Stealth Cruisers can reach that same level of power much more easily.
The Federation Cruisers. Their Artillery weapon (beam or flak) takes a long time to charge (making it often useless until fully upgraded) and occupies a valuable system slot, especially when compared to Advanced Edition systems.
As far as crew examples go, humans. They trigger no blue events, have no special abilities, and are only effective in combat when against Zoltans or Engi. Slugs have the same stats as humans, but also have telepathy (which was further improved in Advanced Edition) and can trigger blue events. The Advanced Edition mercifully gave them slightly faster skill progression and a new blue option.