Level passwords:
Use the axe or sword to change the question marks on the password screen. The number in the password corresponds to a platform, and the letter is the actual value. Example: To enter 2D, change the question mark on platform 2 to the letter D.

Level Password
After snake bosses 2D 4C 6A 8B
After large bat 1B 2D 7A 8C
After grim reaper 3D 4B 5C 6A
Dragon's lair 1A 3B 5C 6D

Extra red hearts:
Enter Level 1, Scene 1, and search for the red heart that gives Dirk an extra life. After collecting the heart, exit the level without losing a life. Re-enter the level, and get the heart again. Repeat this process as needed.