For anyone having problems with the sharedArrayBuffer alert. Please try this link:
https://itch.io/embed-upload/7911361?color=000000
Also, Chrome should work just fine as is.
I did allow sharedArrayBuffer, but it is still an experimental feature. It does work in some browsers and doesn’t in others as it seems. This direct link to an embedded game should be a workaround that works in most browsers.