Type 'T' then CHEAT CODE and finally Enter...

MPGOD	God mode
MPKFA	Lotsa weapons
MPAMMO	Full ammo
MPCLIP	Spectator mode (no clipping)
MPHEALTHY	Fills up your health
MPWHEREAMI	Displays your coordinates
MPHIDEME	Hides your coordinates
MPBEEFCAKE	Increased Power (more gore)
MPKILLEMALL	Kill's all monsters on level
MPSPEEDUP	Increases your speed (1..5)
MPSTRONGER	Increases your strength (1..5)
MPCALEB	Changes your character model to Caleb
MPOPHELIA	Changes your character model to Ophelia
MPISHMAEL	Changes your character model to Ishmael
MPGABBY	Changes your character model to Gabriella
MPBERETTA	Gives you the Beretta, type twice for dual weapon
MPSUBMACHINEGUN	Gives you the Submachinegun,twice for dual weapon
MPFLAREGUN	Gives you the Flaregun,twice for dual weapon
MPSHOTGUN	Gives you the Sawed-off Shotgun, twice for dual weapon
MPSNIPERRIFLE	Gives you the Sniper Rifle
MPHOWITZER	Gives you the Howitzer
MPNAPALMCANNON	Gives you the Napalm Cannon
MPSINGULARITY	Gives you the Singularity Generator
MPASSAULTRIFLE	Gives you the Assault Rifle
MPBUGBUSTER	Gives you the Bug buster
MPMINIGUN	Gives you the Minigun
MPLASERRIFLE	Gives you the Cobalco Laser Rifle
MPTESLACANNON	Gives you the Tesla Cannon
MPVOODOO	Gives you the Voodoo Doll
MPTHEORB	Gives you the The Orb
MPLIFELEECH	Gives you the Life Leech
MPGOBLE	Writes 'Brian L. Goble is a programming god!'
MPSCORPIO	Writes 'Brian L. Goble is a programming god!'
MPTOTARO	Writes 'Jim Totaro is da man!'
MPSUPERZUG	?
MPGOSHOPPING	Gives all items
MPNICENURSE	Gives +25 health
MPREALLYNICENURSE	Gaves 300 health
MPWARD	Gives ward (25 armor)
MPNEWCROWARD	Gives newcroward (100 armor)
MPCARBONFIBER	Gives Willpower Powerup
MPTAKEOFFSHOES	Makes you invisible
MPHERKERMUR	Gives Triple Damage Powerup
MPBEANSOFCOOLNESS	Gives a nice selection of weapons