Type "franchiseme" at the menu, and you should hear the confirmation sound "Halleluya". Then, when in the game, push the following buttons to activate cheats:
W - Hurts yourself
Y - Adds some armor per push
U - Toggles super jump (Can be dangerous)
I - Adds some ammo per push
E - Toggles invulerability
R - Toggles regeneration
T - Toggles haste
Type "iaminahurry" on the in-game menu screen to skip the current level.
Super holy smiting weapon
Type "greyhawknotnat" on the in-game menu screen to obtain the super holy smiting weapon.