I really recommend playing the windows build, because the web build has those annoying loading breaks whenever it plays a sound effect for the first time (the windows build seems to have those as well, but they are much shorter). My knowledge about Godot is limited, but are you sure that there isn't a better way to handle SFX?
The gameplay is a bit bland, and there were a lot of times where I died without really knowing why. Is it possible that some colliders are a bit off? Also not sure why there are health upgrades when everything seems to kill me instantly anyway.