Effect:                                                                                    Code:

Display Secret Passages                                                     At the title screen use controller 2 and press Left, Left, Left, B, B, A, A, A, A, Right, then press start on controller 1.

Level Select                                                                         At the title screen, press Left, Right, A, B, A, Down, and Up on Player 2's controller, then hold A on Player 1's controller By pressing the Select Button, you can select the desired level.

Secret Ending Message                                                       If you can finish Mission 4-4 with 3 lives remaining and 24 grenades remaining, you get a secret message from the programmer after the usual ending message.

Slow Motion                                                                         At title screen, press B, Down, Up, A, Left, Left and Right on the 2nd controller. Now, during the game, press or hold Select to move frame by frame.