Pretty fun. I made it through the first level and could probably have made it through the second if I kept trying. Hitting the sides of platforms makes them drop without pushing the player up, which made it harder. And hitting a platform from below and getting pushed down... Well, it doesn't have to be easy.
I like the sound effects, but the music feels a little bit repetitive (yeah, ten-second loops aren't really my thing) but other than that it fits the gameplay and sound effects. And the art was nice too.