The game is really fun and definitely deserved an HTML build to make it more accessible to testers and get more ratings!
I'm not usually a big fan of this type of game, so I stopped at the third level, just before the first checkpoint. I couldn't figure out how to reach it, and having to restart from the beginning every time got a bit frustrating after around 6 attempts hahah. But I'm probably not really the target audience for this kind of game, so I'm not sure I'd consider that something that necessarily needs to be changed.
I also struggled a bit with the rebound mechanic. It took me a while to realize that I had to press W and the Down Arrow at the same time, rather than just the Down Arrow. It was probably explained somewhere and I was just trying to go too fast hahah.
I also did struggle with navigating the menus and settings without knowing the controls. Since they're keyboard-only and the key bindings aren't explained anywhere, it was a bit difficult to figure out how to navigate them at first. I'm guessing you're already aware of that, though!
The SFX, music, and art all work really well together, and as I said, the gameplay itself is really engaging. I think the core mechanic is very interesting, and the game definitely deserves to be developed further after the jam! Really enjoyed it, well done !