Level Select:
Load the game & press L2, L2, R2, R2 when the message 'Checking Memory Card' appears. A level selection screen will appear when the game begins.

Baby Mode:
Press L2, L2, L2, Select, Select, Select, R2, R2, R2 when Start flashes.

Invincibility & Items:
Pause game play & press L1, L2, L1, L1, L1, L2, L2, L2, Circle, Triangle, Square, Circle, Triangle, Square. The ninja will turn into a skeleton to confirm correct code entry. Repeat the code to turn back into the ninja while keeping the extra items.