I very much like the idea, a platformer based on a musical rhythm. The minimalist aesthetic is also fitting in my opinion. The track can get a bit repetitive, but then again, it is not obnoxious in any way. The hitboxes and physics could use some refinement; at places, my character floated in the air, apparently supported by the adjacent box. This possibly also caused a few failing jumps.
Sadly, I could not get either the web version or the Windows version to work reliably. The suggested Windows version suffered from some mysterious issue where arrow keys move the character extraordinarily slowly, at some 1/10th of the normal speed; the web version didn't have that issue, but instead suffered from the mentioned-above audio reliability issue.
In short, seems very promising and I hope to see a game with technical kinks straightened out :)