I think this is an interesting idea. I had a few problems as I was working through the levels - the player kept getting hung up, sometimes on an edge after jumping, sometimes just walking across the platform. At one point I went off the left side of the screen and couldn't get back on, had to alt-f4. And I got to the boss level, but nothing I tried did any damage to the big chicken. I think you've got a great start here - hope these comments help you in case you want to keep working on this one!