This is great! The visual style and gameplay remind me of the many many puzzle games made in flash, the concept is simple yet works really well, you have a good amount of interesting things (ie, buttons, platforms, etc) that I could see you expanding this even further. The one thing I felt was missing though was sound. I think this definitely could have benefitted from a drop sound, an impact sound, and a sound for when you complete the level. I also felt that the initial push you need to give the ball was a bit clunky and unpredictable, but it did the job in the end.
Overall though, great work!