Thanks a lot for your time, I don't have a good eye for visual issues and you noticed a lot of them!
As for coyote time, it's currently implemented with 0.1 seconds of delay. It used to be 0.14 seconds, but because there is a double-jump glitch I reduced it (for now, I'll change it back once it's fixed)
Also it really makes me happy that the music fit so well.
That's the only thing I can do properly since I'm basically just a game composer with free time.
Oh and thanks for the screenshot, it's much easier for me to fix things like that! Good luck on your project, it was one of my favorites!