I really like the games you make since they take a lot of thought and mental stress to figure out. Of course since I was lazy when I played I didn't really try to get a low score, but if I were in the mood for a good puzzle I'm sure I would find this game really entertaining. Great music too, got me into a thinking mood!
Perhaps on later levels you could add some more bubbles to this for added difficulty, or perhaps more levels in all with random starting colors or something. It would just give the game more replay value.