Cool idea!

Had a lot of fun with this! Didn't experience any bugs and the levels were well designed. It was sometimes a little frustrating to hit the small platforms and the minecart, though, which required lots of moving back-and-forth and trial and error.

The second room is devilishly good. In later levels I found myself paying this gem like a pool game always thinking not about the landing point, but the radius around this point that will be available for my next move.

If I was to suggest a little improvement, I'd say do something to alleviate the backtracking. Sometimes you miss the shot and have to do a slow 180 twice before you can try again.