Fun but severely flawed
Things that bugged the hell out of me:
-Having to press the up button for exactly .00001 picoseconds to do a short jump
-Rubbing against the sides of spikes kills you
-Sometimes gravity would not switch when I told it to, killing me
Aside from that it was pretty fun. The "get through the game without dying" medal is like a joke, but the rest of them are doable. Plus the game is just the right length so that playing through it twice isn't brain-explodingly boring.