• Play this co-op with three people. Four makes the ending much harder (because of bugs) (has improved with latest update)
  
• Keycards are spawned at random in areas.
  
• Follow the markers carefully. If you e.g. head to a keycard, but don't pick it up, the marker will disappear and it will be very hard to find the keycard again.
  
• Never travel alone. You bleed to death after 15 seconds of downtime and there is no way to respawn other than disconnecting and reconnecting.
  
• Help your friends up when they are down by going towards them and pressing (e)
  
• Shoot with bursts for optimal accuracy
  
• Use (v) for voice chat. Communicating with your team is always important!
  
• Press (k) to commit suicide if you get stuck. If the whole team commits suicide the game will restart with everyone alive.
  
• Don't move while in an elevator, that increases the probability of falling through the floor.
  
• Robots can see your flashlight and will react to it, this is not necessarily a bad thing!

• CTR = Combat Training Robot
  
• Keycard = looks like a phone with a yellow screen
  
• Marker = square tilted by 45°, sometimes contains a letter
  
• Alpha (marker with A) = Primary objective
  
• Bravo (marker with B) = intermediate step to get to A

The first thing to do is to exit the transport.You might notice that most doors are locked right now, we need to get the power on. There are two staircases that lead down in the landing bay. Both have access to the ventilation system.
From the ventilation system you can get into the central storage area. This area has quite a few CTRs. At the center are two staircases that lead down to two computers with a button. You have to activate both (the lights have to be green, if you press twice you'll deactivate it again).
Now that the power is on again you can exit the central storage area through the doors, then go up the stairs or the elevator. Now you need to reboot the computer systems to get access to the top floor (crew quarters).

Take the elevator (all non-dead players have to be present) or go up the stairs (past the locked floor, all the way to the top). These are the crew quarters, you have to find a keycard in one of the rooms. Unfortunately shortly after you arrive the power fails. You have to go down in the corridors within the crew quarters. In one of the four furthest rooms here is a power thingy that you have to activate. Be careful, while you do this lots of CTRs will spawn nearby.
Go back up and search the living quarters for that keycard. Remember that locked floor you crossed while going up? Well, it should be unlocked now.

This floor is very confusing, but it can easily be divided in three parts:
The top (labs), middle (more labs, with the botanical gardens in the center), bottom (server hall).
You arrive in the top part. There will be a keycard somewhere here, or below. Follow the indicators to find it. Once you have this keycard, head for the botanical gardens, they are on the middle level of the lab floor (look for a corridor with black windows). In the botanical gardens is a staircase that leads down to the server hall.
Shoot all CTRs here, it'll make it easier.
Now mess with the servers (press the button) to finish you primary objective. An alarm will go off. This is good. Leave it on! Lots of robots will now spawn. Shoot your way back up to the Crew Quarters.

When you arrive on the top floor again head to the central hall. The elevator (grey square) that was previously blocked by tables and chairs is now clear.
If you are one, two or three players this shoot be quite easy. Just make sure everyone is standing on the square, as close together as possible (hugfest!)
If you are four ... this can be quite hard. Keep jumping, crouching and running into each other to get as close as possible to the center of the elevator.
You may want to all leave the square and try again a few times.
(this has improved with the latest update)

IF you succeed in getting the elevator to bring you up, AND not one person falls through the elevator floor: you won the game!
ELSE: bad luck, the bugs won.