Pretty Good.
Since this appears to be one of your first flash games, I'm going to be nice and rate it a 4 out of 5. As I can tell, all you did was just watch, or take, some one's tutorial, and try to make it your own original thing. Most would look down upon that, but coming from someone who once did the same, I completely understand. Plus, you can't go wrong with Kirby music :D Grant it, that first platform to the right of where you start is a bit difficult to jump from, but over all, pretty good.