the only ones i now of are 3arc unlock which will unlock every level in campaign and "five" the zombie mapZork which is a typing game on the terminal 3arc Intel which unlocks all Intel CIA data...
Yes. There are many. To enter them, you continuously, while in the chair at the main menu, tap RT and LT (R2 and L2) to get up (getting an achievment.) Then, go to the computer and hit X/A. Here, you...