I really love forum mafia, but it requires too much effort.

I have a tendency to overfocus on things to the point where it causes me physical harm.

A forum mafia game is a very challenging social puzzle that basically has no upper limit to the amount of effort you can put into it, so it can be rewarding if you try very hard.

Even if I tell myself to take something less seriously, I get swept up by the allure of an unsolved problem and trapped in focus.

Another aspect is that the reward gradient is fairly constant, it always feels like you're making progress after every post (and this isn't really illusory, you really do need to immerse yourself gradually to develop a sense of the gamestate).

Other sorts of puzzles often have a few moments of sudden insight interrupting blind exploratory stumbling.

You never feel stumped in a forum mafia game because there's always more you can do.

It's easier to take a break from a puzzle when the next big insight doesn't feel reachable for now, but if there's lots of small insights, it never feels like the right time to stop.