Cute game! I love that kind of puzzle games. I'm amazed at the music too, you managed to make one for each level and that sure fells more polished. Reminded me some shareware games on Amiga too ;)
Thanks! The triangle-wave music is as much an homage to old DOS and Amiga games as it was a limitation of my own skill. Lemmings is a childhood favorite of mine, so that's probably a subconscious inspiration.