Codes

Type STRETLAMP at the options screen. This gives you:

[Grey +] Level up
[Grey -] Level Down
[1] Invulnerability
[2] Lose a life (why?!?)
[3] ??
[4] Restart Level

Cheat Mode

Type goldfish and press [Enter] to enable cheat mode. Press one of the following keys to activate the corresponding cheat function.

Effect - Key

Temporary invincibility - 1
Level skip - 2
World skip - 3

How do you consider this information:
1 2 3 4 5