This game has a great feel to it. I really like the art/perspective of gameplay. Using the crystals as the switching felt a little awkward, but it wasn't hard to do -- just a minor thing.
It looks like you didn't rig up the credits screen! I went to look at all your names and didn't get to see them.
It was a little shorter than I would have liked, because the atmosphere was feeling great. I would love to play more levels. Great entry!