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.
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.
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.