>This reminds me of a mod for Rimworld that adds in other people's failed colonies and decays the structure making a real ruins from other people's playthroughs of the game. Awesome concept

This sounds like it would be a great mod for Factorio. Adds other players factories but in a dilapidated and decayed state.

Reminds me of bones files in nethack.

I don't know why but it made me think of the original premise of Drivatars in Forza games - Microsoft selling it as an "AI" learning how you drive, then your individual driveatar would be submitted to Xbox Live and would randomly appear for other players in their offline games, but it would drive just like you drive. Really cool concept, of that "footprint" of your play appearing in other people's games.

Shame that it just languished to a point where I think Microsoft completely lost both interest and control over that feature, where in Horizon 6 it just gives you the exact same few driveatars every race, and somehow no one at Playground Games is interested in fixing this. At this point I strongly suspect that they literally don't know how to, the knowledge is lost in the depths of the netcode.