Result

Cheat

Big head

R Stick down - R Trigger - Down - Up - A

Gain gems

DPad Right - DPad Left - A - B - A - B - DPad Right - DPad Left.  Then  use A, B, X, Y, and Black to add different colored gems.

Gain health/power

Hold DPad Left while pushing the Right Stick to the right, then rotate the Right Stick 180 degrees clockwise.  Press A - X

God mode

X - Black - White - R Trigger + L Triggers - Click both sticks

Invincible

X - Black - White - R Trigger + L Trigger - Left + R Stick down

Never gets dark

A - Right Stick down - B - Right Stick down - L Stick down