Ninety-nine lives:
Pause the game and press B, A, Down, B, A, Left, Down, Right, Y, Up.

Invincibility:
Pause the game and press C, Right, A, Z, Y, Left, A, Right, Down, B, A, B, Y.

Unlimited heartstones:
Pause the game and press Left, A, Z, Y, C, Right, A, B(2), Y, Down, A, Down(2), 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.

Bouncy mode:
Pause the game and press C, Right, A, Z, Y, B, A, Left(2).

Jet pack:
Pause the game and press C, A, Left(2), A, X, B, A, B, Y.

Super sword:
Pause the game and press Down, Up, Left(2), B, Up, Left(2).

View map coordinates:
Pause the game and press X(4), Y(4).