Ah, it's a short jam, so I didn't have the time to squash many bugs on platforms other than the most commonly used (Chrome and Windows Desktop). I just tested on Firefox and noticed a ton of graphics and sound issues as you described, most of the sounds are not playing and the pixel perfect camera isn't working. Tbh, Unity's WebGL exports and plugins prioritize Chrome and just doesn't support other browsers quite as well, so these kinds of bugs are often low-level and difficult to squash.
Please consider reevaluating the game on Chrome or Windows Desktop, it would mean a lot to me.
I really appreciate you bringing these issues to my attention and following up to help me fix them. I'll put a note in the description that the game is best played on Chrome.