Sorry for such a late reply. No the game should just play in the embedded window. I have no means to reproduce issues that may occur on other systems at the moment. It's Godot Engine v4.3 exported for web. I appreciate the heads-up, since I was unaware this could have issues like you mentioned.
Viewing post in The Demon Robot Vacuum Cleaner jam comments
I /think/ its just a firefox issue. I've only used unity and its my first jam and I noticed basically all of the godot games behave poorly in firefox for me, but work a /little/ better in safari. I'm guessing this is just some things that are not well optimized. Maybe its fine on windows firefox, but I only own macs so I am unable to test it.
Anyways, probably not worth worrying too much about because only weirdos like me use firefox :-P