I played it in browser. Can tell exactly why: maybe something to do with crouching and or button spawming.
For the music part: i would always suggest to at least play something.
I have just figured out what makes it crash. Its because the browser closes a tab when ctrl + w is pressed. I didn't know this was a thing. The fix is to play in fullscreen mode via options or pressing w before ctrl. I have added this into the game description now.
Yeah I really wanted to add music, but I tought better none than something rushed that sounds bad or doesn't fit at all.