Brother has Doom 3. He has been playing it since half past eight, and has only just stopped. I have been watching and offering suggestions (like "Fucker, don't shoot with something you've got no ammo for." and "The dead cunt's behind you!"). We have both been scared shitless.
It is the God of games.
Also: Doom Cube is a really, really cool name for something that I am sure I have heard before, but Google doesn't tell me anything.