the mechanic of throwing your ball is cool! fact that it glows would also lend itself well to some puzzles maybe? I was a bit sad when the main menu music didn't continue to play during the game because that track is great!
Would love some extra levels and some polish! giving the enemies collision you can stand on was a bit annoying somethings, like I accidentally jumped on something and got stuck taking damage. Having the camera not follow you upwards when you jump unless you pass a certain threshold would be a welcome addition too! sometimes when you jump, the platforms you want to land on disappear from you field of view, and jumping and trying to hit something is also hard when that thing doesn't stay in the same spot.