Press [Esc], then hold [F12] and press the following arrow
 keys:

 U,U,R,R,U,U,U,U - Unlock all doors
 U,U,U,L,L,L,L,L - Full Health
 U,U,L,L,R,R,L,L - Max Sword Power
 L,R,L,U,R,U,U,U - Level Skip