Various cheats
     While  playing, press ` (tilde) to bring up the console. Type any
of the following cheat codes.

Cheat code:         Effect:
god                 God Mode
loaded              All Weapons
slomo #.#           Change Speed (0.1 to 1.0)
fly                 Fly Mode
ghost               No Clipping
walk                Disable Fly/Ghost
allammo             Refill Ammo