Up= U , Down= D, Left= L, Right=R
If you want to unlock all cheats, In the main menu type::
U,U,R,U,U,D,U,U,L,D,R,U
You will hear the monster laughing, which means the cheat menu is unlocked, now go and use it in the extra menu.
If you want to Jump to next checkpoint during the game, type:
R,R,D,R,R,L,R
Full Ink Marker, during the game type:
L,L,R,R,L,L,U
ENJOY!
