OPENING NOTE:

Permanent robots are ones that you never lose and always have control over unless they die, save for RIZZO. Temporary robots will despawn if not active for a certain period of time after being hacked, or also, apparently, based on proximity to RIZZO, but I've not confirmed that yet. Robots that respawn will generally do so back to their set paths, and in RIZZO's case, back at the starting point. You can glitch out certain robots like the bridge SKUDs to be spawned back in different spots which can be handy, but I haven't confirmed how this works yet.

RIZZO: Permanent respawning starter robot. Great for sacrificing in places as it will always respawn back at the starting point of the game. Decent speed overall, great for most parts. Used most of all in Any% at the moment.

Important Robots ("password" NAME):

"plugin" IGOR: Slow hacking robot, permanent but won't respawn. I think grabbing the 25% speed increase rampak is a must for this one in Any%.

"labor" SKUD: Red fast attack robot, temporary and respawns. Great for sending out to areas of the game you don't wish to waste time and more important robots on. Has a unique property where its camera hitbox extends further out than most robots, allowing you to peak through walls and shoot at things you normally wouldn't be able to. Great for skipping GORT with at least one letter for the OVINE secret.

"thunt" ANNEXA: Flying, observing defenseless robot, permanent but won't respawn. This robot is important in all categories for getting to the "Logic Island" (Island with the Church on it), as only ANNEXA can get to the teleport pad to swap out with other robots. No other real uses I know of yet.

"iron" GORT: Red short robot with high radiation tolerance and fast self-repair, slower than IGOR. Pretty much necessary for categories beyond Any% as it can shoot and destroy hidden passage walls. Permanent but probably doesn't respawn seeing as you find it in a far out building on the east side of the river.

QUEEN: This is a boat robot used for sending robots over to the hidden island. It's the one robot that you don't unlock with a password but instead activate with two modules from two specific computers in the game (as seen in the Any% run), which you then must combine on a computer inside the lighthouse, to gain a key module that needs be equipped by a robot (normally IGOR) to finally gain access to this robot. It moves fast, and can be used to explore the ocean to an extent.

"7up" KOKE: A robot vending machine that can pilot AVIATA. Nope, I don't get the joke either ("Coked" up pilot? Gosh that might be it). Doesn't shoot, doesn't respawn and only has mild radiation tolerance for the island you retrieve it from.

"wirgin" AVIATA: Airplane, permanent but one time use for endgame. You press Q to accelerate off landing pad (making sure you're facing the right way on the landing pad, there's a bug that puts your camera the opposite direction behind the plane and you don't have enough track to take off from there), and WASD is reverse Y axis for take off. You can keep accelerating in the air, as the plane only has that one objective you must safely navigate to.

Miscellaneous Robots:

Cameras: Two cameras on the hidden island. Their purpose is simply to let the player know there's that island out in the ocean, and the outside camera appears on the minimap giving you an indication of where to go.

"labor" LEDDI: Pointless robot, visually the same as GORT but weaker firing weapon and despawns when not in proximity to RIZZO or whatever. Best to ignore them, and they will ignore you in return unless fired at.

"scabr" RAT: Tiny defenseless variant of starting robot, fastest robot on land but temporary, out of the way, hard to hack and also dies and/or despawns easily. It's the one other robot that can peak through walls, but it's useless overall given its cons. One interesting thing of note though, I randomly discovered a glitch crossing the bridge where I got it to float up into the air off one of the slopes. I have no idea how I did it, or how to replicate it. I think the game keeps a routine check on a robot's ground position and will snap them back in place after a bit, so I doubt flying to the hidden island with this robot would ever be possible, but it'd be nice to test it out again in the future.

"kwikfit" DOC: Purple repair(?) robot. Defenseless, permanent and I've never figured out its purpose, in all the time I've spent playing this game. Doesn't respawn. There's a rampak for it but that's the furthest I ever got with it. Best to ignore it for now.

Miscellaneous Passwords:

"floss" "gremlin" "retro" "nibbl" "tazor" "razor"