Great presentation - extra points for making sure the cursor changes when hovering over the buttons - but I wish you stuck with the theme more. Maybe it's because I have a big monitor, but even without fullscreen the other levels looked more empty than the first one. I wouldn't have minded keeping the Windows UI. With it gone and the level art not really looking like something from MS Paint, the game stops sharing anything with the source.
The controls had me a little confused for a while, but I got used to them. I really didn't enjoy the last level, however. There were some nice ideas, but platforming while barely being able to see your character was not enjoyable, especially since I beat it another time since I wasn't sure I got it the first time.