Press R to restart if you bump into the freezing up issue. Unsure what causes it. Only happened once on my side, so we couldn't catch it in time. You press escape to exit out of the options menu.
Hmm... I did press "R" to restart, but it only kept getting worse... Like at the start I could move about 5 times before freezing, but after a few restarts I could only move 1 time before it freezes.
That's really weird. I've never encountered that, and I can't seen anyone else encounter that either. Could I maybe ask what browser you're using? In case it's browser dependant?
It could potentially be hardware dependant too, but I don't want to pry.