Really good gravity platformer.
There are a few games like this out there, but this is one of the best.
Controls were easy to use (thank you for not reversing left and right when you switched gravity!), a little loose, but still pretty good.
The difficulty wasn't terribly hard and to get all the gems you just had to think for a second.
Only thing I didn't like is that I worked hard to get all the gems but didn't get the medal. :(
I must've missed one on the earlier levels or something, oh well. Good job.