Pause the game and press C, Right, A, Z, Y, B, A, Left(2).
Invincibility
Pause the game and press C, Right, A, Z, Y, Left, A, Right, Down, B, A, B, Y.
Jet pack
Pause the game and press C, A, Left(2), A, X, B, A, B, Y.
Level select
Pause the game and press Left, Up, C(2), Y, Up, C(2), Y. Resume game play, hold A + B + C, and press Start to reset the game. Enter the options menu and use the new "Test Start" option to select a starting level.
Ninety-nine lives
Pause the game and press B, A, Down, B, A, Left, Down, Right, Y, Up.
Super sword
Pause the game and press Down, Up, Left(2), B, Up, Left(2).
Unlimited heartstones
Pause the game and press Left, A, Z, Y, C, Right, A, B(2), Y, Down, A, Down(2), Y.