Jumps are too floaty. First level was a bit bland, but the new mechanics after that were neat.
Unfortunate that it ended right when it was getting to the fun part, but puzzles don't exactly write themselves, eh? (Well... unless they're randomly generated puzzles... but that's unrelated.)
Interesting puzzle ideas - found the last two levels to be very challenging. Side note - you should use something like py2exe to package your game so that people can play without running from source.
Unfortunate that it ended right when it was getting to the fun part, but puzzles don't exactly write themselves, eh? (Well... unless they're randomly generated puzzles... but that's unrelated.)
Overall, good job!