There are apparently arcade boards and games I didn’t know about. For example, have a look at the arcade boards and games on this page. I probably hadn’t heard of some of them because they never came to the US. Anyway, it looks like they are still making scrolling space shooters in a contest to see who can put the most sprites on one screen.
Also, I noticed that klov allows a search by number of simultaneous players. Good for finding 4 player games for your MAME party…assuming you were nerdy enough to have such a party…uh…not that I am…OK OK, there’d be 4-player games and pizza and DDR and karaoke and…