Press [Esc] during game play and select "Options".
 Then, click in the lower left corner and enter one
 of the following codes to activate the corresponding
 cheat function.
 
 Big enemy heads - type EGOTRIP
 Invincibility - type BEEFCAKE
 All weapons with unlimited ammo - type SWEET
 Display frame rate - type FRAMERATE
 
 For Phillip enter PHAERT
 For Terrence enter RAFT
 For Jimbo enter STARINGFROG
 For Ned enter HAWKING
 For Skinny enter VEGGIEHEAVEN
 For big heads enter MEGANOGGIN
 For pen and ink mode enter PLANEARIUM