Hiro kills with one hit in Single Player Mode:
While pausing the game press L1, L2, Up, Down, Left, Right, Triangle, Square, X, Circle.

Make Hiro invincible in Single Player Mode:
While pausing the game press L1, L2, Circle, Square, L1, L2, Circle, Square.

Level Select:
At the Main Menu press L1, L2, X, Triangle, L1, L2, X, Triangle.

All Magic:
While pausing the game press R1, R2, L1, L2, X, Triangle, Circle, Square.

All Characters for Multiplayer Mode:
At the Main Menu press R2, Circle, X, Square, Triangle, Right, Down, Left, Up, L2, L1, Circle, Square, L1, L2, L1, Circle, L2, Square.