Enable cheat mode:
During game play, press X, A, B, Y, A, B, Y, X, B, Y, X, A, Y, X, A, B on controller two.

Increase keys to nine:
Enable cheat mode, then press Left on controller two.

Set time remaining to 5:59:
Enable cheat mode, then press Right on controller two.

Nine smart bombs:
Enable cheat mode, then press Down on controller two.

Nine lives:
Enable cheat mode, then press Up on controller two.

Level skip:
Enable cheat mode, then press L on controller two.