Avatar is a lemming in bed because this account wasn’t intended to be used except for creating communities… and then my instance announced it was closing.
The big one in the UK is UK Games Expo. The next one is 31st May 2024 https://www.ukgamesexpo.co.uk/
This is making me think of the Oniverse games. Onirim is the only one I’ve played, but it’s solitaire, can be played two player (co-op), has a specific deck, you’re trying to make it through to the end and win (there are expansions which can be added which are only a few cards but completely change the game). It has been a very long time since I’ve played it so can’t actually remember how it works, but at one point I was playing it loads. It’s definitely worth looking at as it ticks a lot of the boxes on your list.
Rubbish!