Very nice looking, I love it!!!
Are the Celeste vibes on purpose, because if yes it's working :)
The music is also beautiful. Props to Mr.Potenzoni, is that right?
As for bug reporting:
It lags, like a lot. I imagine this wouldn't be as much a problem with a non-web version, but I do have a few hypothetical suggestions for fixes. Do you happen to have load() calls anywhere? If yes, maybe replace them with preload(). Other than that, it's a bit weird the music also stops when it lags... if it isn't already it might help to load the music as a singleton.
All the best with your game, folks!