Unlock Alternate Intro:
Complete the game, then start another game to view an alternate introduction sequence. 

Conserve Revolver Ammo:
Instead of waiting for the person in the electric chair to die, kill him with the sickle that is found in the cell.

During gameplay hold L + R + X and enter one of the following codes: 

Full Health Meter:
Down, Down, Down, A, Up, Up, Down, Up, A. 

All Weapons and Items Except Gonzo Gun:
Down, Up, Down, Left, Right, Left, A, Up, Left, Down, Right, Up, Right, Down, Left, A, Down, Down, Down, A, A. 

Get Gonzo Gun:
Left, A, A, A, Right, Left, Right, Left, Up, A, A, A, Down, Up, Down, Up, A. 

Refill Ranged Weapon Ammo:
Left, Left, Up, Down, Right, Left, Right, Right, A. 

Refill Gun's ammo:
Right, Right, Down, Up, Left, Right, Left, Left, A. 

Negative Karma:
Left, Left, Down, Up, A. 

Molotov Cocktails:
Down, Down, Down, Up, Up, Up. 

Grenades:
Right, Right, Right, Left, Left, Left. 

Xombium Bottle Full:
Right, Right, Up, Up, A, Left, Right, A, Right, Up, Right, A. 

Suicide:
Down, Down, Down, Down.