I really enjoyed the game, I think I spent at least an hour trying to beat it :D Loved the simple yet polished-looking aesthetics. Pretty unique and addictive idea especially since levels are so well designed.
There's just some small problem with the physics of the ball (it doesn't immediately stop when you stop pressing A/D) so jumping on those tiny platforms was in some cases unnecessarily hard. It sometimes happens after teleporting too, got me killed a few times this way.
Also not sure if there's something wrong with ground check or all inputs are not being registered, but double jump was really hard to execute well. It sometimes doesn't work at all which particularly sucks when you have to plan your jumps so accurately in later levels.
Amazing game!
Btw I was wondering what's slowing down the game so much? It's lagging even in windows build, not a lot but still noticeable.