Cheat mode 
At the main menu, hold L1 and press 
X, X, X, X, X, Circle, R1, R2, R2, R1. 
Press Start during the game and activate any option on the cheat menu.

Infinite lives 
At the main menu, press 
Left, Left, Left, Right, L2, L1, R2, R1. 
Press Start during the game and activate that option on the cheat menu.

Infinite ammunition 
At the main menu, press 
Down, Right, Up, Left, L2, L1, R2, R1. 
Press Start during the game and activate that option on the cheat menu.

All items 
At the main menu, press 
Right, Left, Up, Down, L2, L2, R2, R2. 
Press Start during the game and activate that option on the cheat menu.