review
Honestly better than most flash games I've played. I'm not sure you did the hit detection extremely well, but it seemed ok most of the time. Disregarding the basic premise of the game, and the obvious over simplicity, I have a few observations or suggestions that I think would make the game better as it is right now...
First of all, you can't move from the top of the screen to the bottom, but you can from the bottom to the top, and left to right and right to left, that seems very strange and counter-intuitive, not sure if that was just an overlook or...what...
Second, use a variable to make the mute toggle, instead of constantly change from muted to unmuted while you hold down the m key. That makes it easier to actually mute the music if you want to.
Third, a key to restart, like hitting 'r' would be nice, so you don't have to play out the game if you already messed up badly.
Fourth, mochi scores are very easy to add into your game if you take the time to look into how to do it, and they add a lot of replay value to even the simplest games.
Anyway I hope you find any of this helpful, keep at it.