Unlock Dark Knight Difficulty Level
     You  must  be  in  the  PRESS  START  menu. HOLD - L1, L2, R1, R2
(simultaneously)
     Then in the proper sequence (digital pad): DOWN, LEFT, RIGHT, UP,
UP, RIGHT, LEFT, DOWN.

Unlock End-Game Rewards (Mega Cheat)
     You  must  be  in  the  PRESS  START  menu. HOLD - L1, L2, R1, R2
(simultaneously)
     Then  in  the  proper sequence (digital pad): DOWN, UP, DOWN, UP,
LEFT, RIGHT, LEFT, RIGHT.

Unlock All Upgrades
     You  must  be  in  the  PRESS  START  menu. HOLD - L1, L2, R1, R2
(simultaneously)
     Then  in  the  proper sequence (digital pad): UP, UP, LEFT, LEFT,
RIGHT, RIGHT, DOWN, DOWN.

Unlimited Combo Meter
     You  must  be  in  the  PRESS  START  menu. HOLD - L1, L2, R1, R2
(simultaneously)
     Then in the proper sequence (digital pad): LEFT, RIGHT, UP, DOWN,
RIGHT, LEFT, DOWN, UP.

Unlimited Health
     You  must  be  in  the  PRESS  START  menu. HOLD - L1, L2, R1, R2
(simultaneously)
     Then in the proper sequence (digital pad): UP, RIGHT, DOWN, LEFT,
UP, LEFT, DOWN, RIGHT.