Gamer has been removed
Pretty easy.
1. Play through the level keeping the entities & monsters in their containments as best as you can. (Use the center charging stations!)
2. When the Lesser Containment fails, replace the batteries to fix it, maybe 30 seconds after that the big troll guy breaks out (AI will say something like "Unknown Entity has escaped")
3. Grab a fresh battery from the center (unless you already have one).
4. Run back upstairs past the incinerator, put the battery in that top hallway to open the One Way Exit, open it.
5. Make your way to the supervisors office (continue along the hallway about 4 or 5 doors down on the right) it's the door with an intercom.
6. Stand outside his office, and wait for the troll guy (you don't have to lure him, he will always find you lol) When he gets there he'll charge the door, not you.
7. Run to the hallway, take a right and keep running back to the elevator (where you started), the door will open, go through the door.
8. Achievement unlocked :)