Various Cheats
     At the Enter Cheat menu, enter any of the following "Codes", then
begin a new game and push Start to access the cheat menu:

Code                    Effect 
UBERNOODLE              Big Head Mode 
HOLASTICKBOY            Stick Men Mode 
STOMPEM                 Big Hands and Feet 
PIPSQUEAK               Small Enemies 
IGOTABFA                Pen and Ink Mode 
WHATSATEXTUREMAP        Gouraud Shading 
LIGHTSOUT               Blackout Mode 
HEEERESJUAN             Juan's Cheat 
AAHGOO                  Zach Attack 
FROOTSTRIPE             Rainbow-Colored Environments 
BEWAREOBLIVIONISATHAND  All Cheats Enabled 
ONLYTHEBEST             View Credits 

Invincibility Bug
     With  your  health  very low, stand in front of a save portal and
allow  your  character  to  be killed. Press backwards into the portal
when  your  character  is being attacked. Save the game and return. If
done  correctly, your character will have zero health, but invincible.
If  you  pick  up  any  health,  you will lose invincibility. You also
cannot press Start with this bug active.