I'm not sure why, but the music was a bit crackly while I was playing in the browser.
Other than that, this is a really neat platformer. Good work on it.
The crackling didn't seem to occur when I was playing the downloaded version. Here's a sample of how it sounds in the browser: https://0x0.st/XZKv.ogg
This was recorded while running Firefox. Chromium has the same effect, although maybe less severe?