I just gave this game a go. It was actually really fun, and pretty good for what it is.
A few thoughts:
1) The controls are fine, but I'm not a big fan of the little bit of momentum that the character has after you release the arrow keys. Especially since there are quite a lot of really tight spots in the game, that extra bit of momentum really throws me off. The part where this really frustrated me was the section where you have to run through three saws, and you have to hide in the area between the saws. I would release the keys to stop, but then the character would continue to slide forward, hit the saw, and die.
2) The checkpoint system could use a little work. I would definitely make them more frequent. Also, I noticed in a few areas, if I fell down a few levels before dying, I'd end up at an earlier checkpoint than the latest one I was supposed to be at. With a game like this, where it's difficult enough to get past obstacles once, it was frustrating to have to solve them multiple times.
3) Love the rotation turning the jump. Nice touch.
All in all, a great first game. Really impressed with the work you've done. Just a few tweaks here and there to improve the experience for the player.