Good, but needs some work...
First off, I thought the animations, though small, were fairly decent, and the sounds on some of the drums weren't that bad. However, the response time is horrible, making it nearly impossible to drum along with the songs using complex beats. Also, I commend you for the small file size, but with any music game, the sound quality needs to be high, despite file size. Work on that, add more songs, and put in some more features like being able to choose the configuration of your kit and the color. I hope you make a version 2 soon.