Enter CHEAT as a password. After game play begins, do not enter the warp and collect all items while moving down. Collect the gem, then the coin at the bottom of the maze to enable cheat mode. Then, press one of the following keys to activate the corresponding cheat function.

Effect - Key

Level skip - [F1]
Fire weapon - W
Activate shield - [Delete]
Bombs - B
Extra lives - L
Energy - E
All coins collected - A
Freeze monsters - F