Invincibility: While the game is paused enter L2,R2,L2,L2,L2,R2,R2,R2,circle,triangle,square,circle,triangle,square. If you have done it correctly you should hear a chime and the ninja turns Into a skeleton.Do the cheat again to change back.
Level select: Remove your memory card then turn on the PlayStation.When the screen says 'Checking Memory Card'quickly press L2,L2,L2,R2,R2,R2.The words 'DELS LEVEL CHEAT ON'should appear.Begin a new game to access the level select menu.
Random Weapon: While the game is paused press R2,R2,R2,L2,L2,L2,R2,R2,R2,L2,L2,L2,L2,L2,L2.
Severely Damage Bosses: This cheat code allows you to weaken bosses to the point where they will only be able to sustain a few more attacks.During any boss battle, just pause the game and press L2,L2,L2,R2,R2,and then triangle 6 times.
Remove ALL Memory Cards from the PlayStation and then when the message 'Checking Memory Card' appears on the screen press L2, L2, L2, R2, R2, R2. If the code has been entered in correctly the words 'DELS LEVEL CHEAT ON' will appear. Start a game to access the 'Level Select' menu.