Type in "flev17" and then press [Enter] at the title screen. If you entered it correctly, the screen will flash to confirm it. You will have unlimited lives during gameplay.

Code - Effect

[F1] - Jump to level 1
[F10] - Jump to level 10
[F2] - Jump to level 2
[F3] - Jump to level 3
[F4] - Jump to level 4
[F5] - Jump to level 5
[F6] - Jump to level 6
[F7] - Jump to level 7
[F8] - Jump to level 8
[F9] - Jump to level 9