Oh, I understand now Eva! I hope you get another call soon telling you that you got the job
It's just a role playing thing we do, there's no system or specific game, we made up a world and then characters and spent ages researching plate tectonics and weather and how a stable ecosystem would work and evolve given various conditions, and spent a few more years arguing about implications, and drawing maps, and then split up a generally-agreed-upon time-line and each of us fleshed out that age, (I mostly worked on the later ice age), and peopled it, and built things on it, and tried to figure out basic trading routes and production areas, and now we take turns telling the story while the others play random people in it. So if one weekend we go camping and play around in that time period where the vegetation pretty much went crazy and took over, and a lot of the people were wiped out with various allergies/toxins/molds/whatever, then sometimes we stumble across ruins from back before the big volcanic eruption, or if you play in the time after the ice caps melted down a bit and the water levels rose so high, your characters might stumble on an old map, and try and convince a captain to take a ship over where there used to be cities and go diving for treasure, that kind of thing.
It's fun, but there's an awful lot of notes.
I dunno what game you'd call that?
Mostly just collaborative story-telling/world-building.