People usually underestimate the difficult of doing an enjoyable platform game with smooth controls and good distances and balancing... and you achieved that! :) Also, I think the level selection emthod is very innovative. I think, maybe, you could add some replayable-factor if you make the levels mutually exclusive, and you can only chose a path to reach a final level.
Overall, this is very well done and I think you should improve and expand it :)