Cheat Mode

Press ~ to bring up a console which enables cheat mode.

First Person View

While in cheat mode, type in +6dorf to enable it.

God Mode

Press the ~ (Tilde) button and type in Impluse 11, and you gte god mode.

Kill of the enemies in a level.

While in cheat mode, enter the code ode to jack.

Large Magic Attack

While in cheat mode, type in impulse 10.

Watch the ending sequence.

While in cheat mode, type in bigfinale.

Codes
Cheat codes

Press ~ to display the console, type one of the following codes, then press [Enter] to activate the cheat
Code ...................... Effect
-6dof ..................... 3rd person view
impulse 43 ................ makes player commit suicide.
noclip .................... Noclip mode.
impulse 137 ............... Plays bonus Audio tracks

Spawn codes

Press ~ to display the console, type pc_spawnthing <code name>, then press [Enter].
Code ...................... Effect
pc_spawnthingbat .......... bat
pc_spawnthingi_bouncebombs Bouncing Bombs
pc_spawnthingwalkinghead .. Demon
pc_spawnthingi_bombs ...... Dynamite
pc_spawnthingfrostgiant ... Frost giant (Boss)
pc_spawnthingicetoad ...... Ice toad
pc_spawnthingknight ....... knight
pc_spawnthingwererat3 ..... Large wererat
pc_spawnthingwererat2 ..... Medium wererat
pc_spawnthingratlord ...... Rat lord (Boss)
pc_spawnthingratmage ...... Ratmage
pc_spawnthingsludgeworm ... Sludge worm
pc_spawnthingwererat1 ..... Small wererat
pc_spawnthingsnowwitch .... Snow witch