Debug ModePause gameplay, hold L1 + R2 and press Up, Triangle, Down, X, Left, Square, Right, Circle. Release L1 + R2 and press L1, R1, L2, R2. Wait a little, then press Start, L2 + R2.
Slow Motion ModeFirst enter the code above, Debug Mode, and use one of the cheats in the menu. Then pause gameplay and press Select to make the game move frame by frame. You can also control the ninjas during this.
Alternate Ayame CostumeAt the Item Selection screen, press Left, Left, Down, Down, Square, Square, Triangle, Circle. Now select Ayame.
Enable Japanese VoicesSelect a character and at the next screen, hold L1 and press Left, Left, Down, Down, Square, Square, Triangle, Circle.
Two PlayersFirst enter the Debug Mode code above and choose Enemy. Choose any enemy. Then choose Pad-2 and run away from P2. When you see a question mark near your life bar, run back to P2. Now Player 2 can move the enemy you have selected.
US Version
Level SelectSelect a character and at the next screen, then hold R2 and press Left, Left, Down, Down, Square, Square, Triangle, Square.
Unlock All LevelsAt the Mission Selection screen, hold R1 and press Square, Square, Triangle, Triangle, Right, Right, Up, Right.
Enable Japanese Voice OverAt the Mission Selection screen, hold L1 and press Square, Square, Triangle, Triangle, Right, Right, Up, Down.
Enable Enemy Layout Selection ScreenAt the Mission Selection screen, hold L2 and press Square, Square, Triangle, Triangle, Right, Right, Up, Left.
Enable Ayame Sexy ArmorPlay as Ayame and at the Item Selection screen with armor displayed as an option, press Square, Square, Triangle, Triangle, Right, Right, Up, Right.