Cheat mode:
Type one of the follow codes:

Result - Code:

Flight mode - fly
Disable no clipping and flight modes - walk
Kung Fu fists - kungfu
Spawn minigun - minigun
Spawn bolt-action sniper rifle - sniper
Spawn fire axe - axe
Spawn Glock handgun - glock
Spawn pump-action shotgun - shotgun
Spawn Molotov cocktails - molotov
God Mode - god
999 ammunition for all weapons - allammo
All weapons - weapons
No clipping mode - ghost

Level list:

the farm-checkpoint 1
cornfield-checkpoint 1
cornfield-checkpoint 2
neighbors-checkpoint 1
mainstreet-checkpoint 1
detour-checkpoint 1
detour-checkpoint 2
hospital-checkpoint 1
the doctor-checkpoint 1
the doctor-checkpoint 2
override-checkpoint 1
override-checkpoint 2
fire-checkpoint 1
escape-checkpoint 1
escape-checkpoint 2
back alleys-checkpoint 1
warehouse-checkpoint 1
warehouse-checkpoint 2
police station-checkpoint 1
sniper rifle-checkpoint 1
headshot-checkpoint 1
sewers-checkpoint 1
sewers-checkpoint 2
labyrinth-checkpoint 1
labyrinth-checkpoint 2
the theater-checkpoint 1
the docks-checkpoint 1
deliverence-checkpoint 1
deliverence-checkpoint 2
city of the living checkpoint 1
city of the living checkpoint 2
heavy gunner-checkpoint 1
fiddlers green garage
fiddlers green atrium
fiddlers green penthouse
annlhilation (final level closing scene) game done