Press Down on the Joystick to crouch, then pause game play. While remaining crouched, hold [Ctrl] + [Help] until the screen begins to shake to enable cheat mode with unlimited lives. Press one of the following keys to activate the corresponding cheat function.

Code - Effect

[1] through [5] - Additional levels
[Enter] - Ground shake
[F1] through [F10] - Level select
[Cursor Down] - Sound louder
[Cursor Up] - Sound quieter
S - Sound test
D - Suicide