Cheat:
Enter "DAGMAR" as a password to activate the following keys:

D = only 1 diamond left to collect
L = extra life
S = skip level
T = more time

Level codes:

Level  4: EDDIE        Level 16: MAINSTREET    Level 28: LETTER
Level  8: MAIDEN       Level 20: FONT          Level 32: DESK
Level 12: DESTROY      Level 24: MAGIC         Level 36: FRONT