FOOM! is a fan-made text adventure based on Doom.
The first thing the player sees when beginning episode one:
Hangar Entrance A dark squarish room. You are just inside the entry bay, which has closed behind you. There's no way out that way. Pillars obscure your view, and the viewport on the right lets in but little light. The centre of the room, to the north, is depressed; a couple of steps lead down to it. A pillar prevents you moving to the northwest but your movement towards your left, to the west, is unhindered. You see a health bonus here. >