Takua Nuva
Finish the game succesfully using all six Toa.
More Bonus
Finish a level with all Lightstones collected as each Toa.
Destroying Dark Cages
Use Nuva Blasts to destroy dark cages. Charge your elemental energy, then immediately press Triangle.
Defeating Makuta
When you are at the end of the game and are battling Makuta. press X(2), Triangle. You should be gliding and dodging all attacks except for the flying bees.
Dodging Attacks And Refilling Your Mana
When getting attacked (this works well when facing more than one opponent), jump and use your shield rapidly. The attack will completely miss and you will refill your Mana. Do not do this with dragonflies and other flying enemies. It may work, but there is less chance of it working. For extra effect, while in the air press Attack. Since enemies are vulnerable when they attack you, they will get serious damage.