I love it, the idea it self (In my opinion) is genius. Also the sound effect, I was a musician for couple of years, and I think the use of piano sound in here fit's perfectly. Can I ask you a question, what software did you use to make the sounds? Or did you record it, I'm asking because I'm looking for one for my self and I can't find a good one.
In conclusion, your game was really fun to play, especially the idea of that many levels and different staff to make your game harder.