It's a really creative idea to have pulled off for a game jam! The only thing I didn't like was encountering levels where you needed pixel-perfect positioning of the blocks when you switch in order to get it to work. If there's some way of making them push each other so they're not overlapping when you try to switch with a little overlap instead of just having the switch fail, and if you can give a little grace period when a jumping block hits a ceiling before gravity kicks in and it starts falling, then that should eliminate the need to be pixel-perfect at those points that I've come across so far.