Nicely done. This is quick to grasp and easy to get into but quite hard to master! I think the collision detection needs a little work, or possibly the level design could have fewer places where you have to be very accurate or else you get stuck in a platform, but these are fairly minor gripes. (I did once get stuck permanently and there's no way to resolve that, when I think I fell downwards while in contact with a permanent wall.) I even like the minimalist music. This is good fun, and surprisingly difficult for a simple-seeming concept!