That's unfortunate! I am able to replicate an infinite loading screen in Firefox. For now you can try downloading one of the desktop builds if you are still willing to give it a try :)
-Updated-
It appears it was the result of exporting with threads enabled! Which is strange as it should be supported in Firefox, but I have uploaded a second version that should work in Firefox at
https://supersleeper.itch.io/firefox-time-talon. Cheers :)