Tenchu Shinobi Gaisen (PSX)

Carry more items:
At the item selection screen, hold Triangle and press L1, R1, Up, Right, Down, Left.

Increase items:
At the item selection screen, hold Triangle and press L1, R1, Up, Down, Right, Left.

Maximum power:
Pause the game and press L1, R1, Right, Down, Left, Up.

Debug mode:
Pause the game, hold L1 + R2 and press Up, Triangle, Down, X, Left, Square, Right, Circle. While playing, press L2 + R2 to access the debug menu.

Debug mode (Japanese version):
Pause the game and press Up, Triangle, Down, X, Left, Square, Right, Circle, L1, R1, L2, R2. While playing, press L1 + R1 to access the debug menu.