Cheat Codes:
Press Esc, then hold down F12 and press the directional keys as follows:

Unlock Doors 		- up, up, right, right, up, up, up, up 
Maximum Sword Power 	- up, up, left, left, right, right, left, left
Full Health 		- up, up, up, left, left, left, left, left
Skip Level 		- left, right, left, up, right, up, up, up 

Thanks to Revolution readers CreatoR(99), Scott Edwards, and Brian Markel!