In Metroid Prime 3 their are a few secrets within the game that are kind offun to use and give you a challenge when fighting.

1.When fighting a Reptillicus on Bryyo and you have ice missiles, use this. When a Retillicus throws its boomerang at you, launch a ice missle at it at the same time and freeze it. When the boomerang flies back it will break the Reptillicus apart. Sometimes you will have to fire a couple of regular shots and 2 ice missiles to freeze it.

2.When in the battle against the SPACE PIRATES on Norion when you exit the section with Generator A and Ridley shows up, when he flies across the base and blasts up alot. If you can manage to hit him in the head he will turn around and fly right towards you.

3.When on Phaaze and your fighting the Auroura Unit charge up your rapid blast when shooting it in the head and you will damage it more.