A slow game (or is someone has a better name please do tell!) is a multiplayer game where you get some action points every day (or twice a day), that you spend on walking around and usually fighting monsters a la CRPG.
Played in a browser those games took like 5 minutes a day to play and were quite popular in the early 2000. Obviously people spent more time setting up groups going hunting or fulfilling some quest, often for weeks and weeks…
Have you played one of would you try one out?
I was part of a PBEM D&D game in college. I’m pretty sure it took us a while semester to accomplish absolutely nothing! But I had fun.