X2: Wolverine's Revenge

On the main menu press Triangle, Circle, Triangle, Square, Triangle, Circle, L1, and then R2.

At the main menu, press Triangle, Circle, Triangle, Square, Triangle, Circle, L1 + R1.

At the main menu, press Triangle, Circle, Triangle, Square, Square, Square, R1 + R2.

At the main menu, press Triangle, Circle, Triangle, Square, Square, Square, L1 + L2.

At the main menu, press Triangle, Triangle, Circle, Circle, Square, Square, Circle, Circle, L1+ R1 + L2 + R2. The Debug menu will be available from the pause screen.