Press [Lef [Righ [Up] [Down] [Lef [Righ [Up] [Down] at the main menu with the "Start", "Options", and "Quit" options. Then, press one of the following keys during game play to activate the corresponding cheat function.

Key - Effect

[F3] - Level skip
[F4] - Player one extra life
[F5] - Player one unlimited lives
[F6] - Jump to level 98