Some say that Rainbow arts got into legal trouble with Nintendo about this. I wouldn't know. I was barely 12 and after a few months later my wrist knew exactly the sequence to get to the end. Years later I learned of this weird game with some Italian plumber guy, and then my little brother got Mario world on his Game boy, but that looked pretty bad and had no style, if you ask me :)
Oh, and it's one of the milestones for Chris Huelsbeck (Music) an Manfred Trenz (Graphics) who went on to make Katakis, which taught the world a few tricks which that old C64 was actually capable of. And I can still hum all the tunes from both of those games.