This is quite impressive for 48hrs. Would fit perfectly in the "silence is key" theme that wasn't picked, it's a shame, cause it was my preference.
Overall it did give me a scare first time, but after that the monster is really easy to dodge, I like the fact that you learn to basically freeze completely once the monster rave music starts playing. I don't see any credits for the assets so if you did them yourself that is a huge accomplishment in this time frame, I could never :)
I do think you might be having issues with capturing the mouse in the web build, it probably works fine on windows , but for the web you can't capture the mouse willy nilly - you have to capture it ON window click. So just include into _unhandled_input another capture specifically on mouse click.