Cheat mode
Type one of the codes during gameplay:

Result - Code:

Fireball gun - sternomat
200 flame thrower rounds - firehurler
Mine field bombs - crotchbomb
Return from dead - hesstillgood
Grenades, missiles, heatseekers - explodarama
Level skip - theresnoplacelikeoz
No clipping - suckdeeznuts
Revive character - chthom
Health, Kevlar vest - chtpos
Invincibility - iamsolame
100% health - healthful
Less damage - thickskin
50 more shotgun shells - carrymore
All items, full health - gimmedat
Missiles and grenades - dawholeenchilada
Shotgun shells - breakyosak
Reduce character size - myteamouse
Spray cannon - shellfest
200 flame thrower rounds - flamenstein
50-100 shot gun shells - shotgun
Spray cannon - thebestgun
Grenade and fire extinguisher - lobitfar
Missiles, heatseekers - titaniii