Hi, I like your game so far. Bird houses as checkpoints are a really nice touch. I am also glad that you did not make caterpillars respawn :).
Unfortunately, I have to report a bug that I have. When I first launched the first level the screen was black, the only thing that was appearing were the tooltips for movement. When I restarted the game, everything was fine until the 3rd level, everything was black again.
EDIT: I have installed latest divers for my graphics card and everything is fine now.