Operation C Cheat Codes for Gameboy

EXTRA LIVES
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.

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

OUND TEST
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.