Unlimited Lives:
Goto the title screen and while holding L1 enter the following:
circle, down, left, up, right, triangle, down
You will now have unlimited lives!

Add Unlimited Crystals to Inventory:
Goto the "Title Screen" and hold L1 and while holding L1 press:
square, square, circle, down, left, right, left, right
Next, start a new game and while holding R2 press "X".
Repeat as necessary!


Unlock Cheats:
Goto the title screen and while holding L1 enter the following:
triangle, left, left, right, square, up, up, left, circle
(during gameplay press L2+R2 to unlock cheats)