Operation C Cheats for GameBoy

On the Title screen, press Up four times, Down four times, Left four times, Right four times, A, B and Start to begin with 10 lives.

On the Title screen, after it stops "waving," press Up, Up, Down, Down, Left, Right, Left, Right, B, A, B, A and Start. S

On the Title screen, after it stops "waving," press Up, Down, Left, Right and Start. "Sound Test" should appear on the screen. Change the selection by pressing A and cancel by pressing B.