In the game, quickly tap these inputs:
Slow Motion: R, L, Up, Down, A, Up, L
Full Health: R, L, Up, Down, A, Up, Down
Gravity: R, L, Up, Down, A, L, L
Punch Mode: R, L, Up, Down, A, Up, Up
Lethal Charge: R, L, Up, Down, A, Black, Black
Bomb Mode: R, L, Up, Down, A, Up, White
Megaforce(Restart Removes): R, L, Up, Down, A, R, R
Nailgun Mode: R, L, Up, Down, A, White, White
Level Select(In Main Menu): R, L, Up, Down, X, Y, B
God Mode: R, L, Up, Down, A, R, L, Black, White
All Weapons: R, L, Up, Down, A, Up, X, A