Hold down F1 while playing the game and type...
(cont holding F1 while typing the code)

mukor - God mode
qsave - Quick Save
pause - Pause the game
frame - Screen Shot
golrg - Makes you real big ( try typing this a lot ! )
btiny - Shrinks You
tough - Difficulty Level
mecam - 1st Person View
gocam - Stationary Cam
spcam - Enemy Cam
bamff - Sends you to the end level
gamma - Changes Gamma Level
dedly - Weapon Enhancer
sepku - Kills you


GameTip:

while playing in any situation you may type
in anything by always pressing F1 and then holding
it by typing in "mukor" that is god mode. "lunar"
that gets you up in the air but be careful dont do
it to much or other wise you'll get stuck

Fun:

bills - Bill's demo type thing
ifall - Knocks you off you feet!!
hicup - Throws you around!!
silky - Stupid Monsters
lunar - Low Gravity
funky - Funky keys toggle
catch - Out of World Trapping Toggle
aiaim - Ai toggle
agrav - Limb gravity

Debug:

bzone - WireFrame/Shading/Nothing/Normal
fpers - Shows "Sound Cache Misses"
goura - Gourad shading
ntrud - Selects An Enemy
plane - Shows Protection And Damage Points
nfade - Disable/Enable Pallate fading
gmode - Faster cycles ( makes everything go faster )
colid - Shows possible collision locations

you can add -god when running the main exe
for god mode also.