To access cheat mode, play normally and get a score of 2,000 or more. Then die and get game over. At the high score screen, enter your name as ENIREHTAK and you should hear an explosion sound as confirmation. You will start each level with a full sword. Pause the game and enter the following codes for the desired effect.

Effect	Code
Adds a minute of time	A + C + Left
Extra life	A + C + Right
Skips level	A + C + Up
Toggle invincibility	A + B + C + Down + Right