This week it’s been Megaman II (1988).
I feel like games before that era had a lot of coin-op focus. Not much content, but hard enough that you’ll be pouring more credits into the machine. That said, I’ve been itching to play Alley Cat (1983), but I don’t have a good setup for MS-DOS games at the moment. I’ll have to see if my Miyoo mini is up for the task.
Sounds like it’s localStorage. But I’d expect that to be covered by “site data” in that option.
It’s a bit like cookies, but just for one site. Some think they can avoid cookie consent banners with localStorage.
Firefox has a page on the topic.