I was digging a little and just wanted to add a few links: https://www.themirror.space/ and https://github.com/the-mirror-gdp/the-mirror
It looks like a competitor to both Roblox but also meta and vrchat, and even mindcraft. Vrchat is free i think, but they own the data.
I see they've adapted the leading OS game engine, Godot, which also let's our personal AI simulate the real world in real time. I wasn't particularly happy with this roadmap tho: '(Future) Marketplace: Easily monetize your games, 3D models, audio assets, and more with one-time purchases or RevShare.' It doesn't take long to convert the project into some shitcoin 'adventure' where nothing is done without coin incentives and people behave like it's all a business.