Really cool game, not my kind of game but it's really smooth and easy to learn, but hard to master. I just feel the game would be better as a simple racer than using the magnets, but that's a matter of tase. Good job!
I playtested every track without magnets beforehand and I can guarantee you that it's a pretty dull experience. I can totally understand if you're not attracted to that sort of game though, it's sorta niche.