How many people can play at the same time?

That depends on the device of course. There are devices like Pac-Man, which is designed for one person. But there are also devices that have, like a pinball machine or a dart machine, a digital display with multiplayer modes where people take turns playing and the device is automatically designed for multiplayer. But of course there are also classic devices like the foosball table, where either two or four people can play, and the XXL foosball table is even suitable for eight people.