One of the few games that I feel was not completed. Rushed to market too soon. Biggest reason? No ingame music
other than the main menu, world introduction, boss-fights, and credits. And the first three are almost identical!
Still, it's a game with a lot of secret passages, hidden areas, and 19 levels (four in each of the four worlds, and three bonus levels).
The control codes are useful to discover hidden objects and pathways.