These can be used on ALL VERSIONS EXCEPT the GBA and DS versions

Enter these on the pause menu:
Big Head Mode: up,down,down,up,right,right,left,right
Infinite Health: U,R,D,U,L,D,R,L
Inf. Scrap: D,D,L,U,U,R,U,D
One hit kills enemies: D,L,U,D,D,L,R,R