Code What it does

DNKROZ.... God mode(and unlimited Jetpack)
DNVIEW.... Same as the F7 key
DNHYPER .... Puts you in Steroids mode
DNITEMS.... Gives all inventory and keys
DNWEAPONS.... Gives all weapons
DNKEYS.... Gives all keys
DNSTUFF.... Gives all inventory, weapons, and keys
DNSCOTTYxyy.... Level warp. x is Episode number, yy is Level number (ex. DNSCOTTY105 is The Abyss)
DNSKILLx.... Puts you in skill level x (0-3)
DNUNLOCK..... Opens all doors and unlocks all locked doors, but only in the registered version
DNMONSTERS.... Turns off (or on) the monsters in the game
DNCLIP.... Walk thru walls
Warning: Being in God mode can crash the game, depending on what you are doing. Being sqished by gears is one example. Warning: The DNCLIP code can be dangerous. It can cause crashes at any time.