At any point during gameplay, press PAUSE. Next press and hold (L1+L2) for 10 seconds and then while holding press D, R, O, L, R, O.
Extra Bombs:
At any point during gameplay, press PAUSE. Next press and hold (L1+L2) for 10 seconds and then while holding press R1, R2, X, T, S, O, R1, R2, O, O, and S.
Extra Health:
At any point during gameplay, press PAUSE. Next press and hold (L1+L2) for 10 seconds and then while holding press R, R, L, D, D, U, T, and O.
Extra Lives:
At any point during gameplay, press PAUSE. Next press and hold (L1+L2) for 10 seconds and then while holding press L, D, R, T, S, X, and O.
Skip To Next level:
At any point during gameplay, press PAUSE. Next press and hold (L1+L2) for 10 seconds and then while holding press X, R1, T, R1, S, O, R2, R2, X, S, and T.
Weapon Power-Up:
At any point during gameplay, press PAUSE. Next press and hold (L1+L2) for 10 seconds and then while holding press R, D, R, and T.