Status: just beginning to take notes
A few to review: Decentraland, Somnium Space, Cryptovoxels, Axie Infinity, The Sandbox.
In general, in 2022, after playing with the above, I just can't get excited enough about the existing systems to take time for a deeper dive.
The only comment I have is that ownership of *MOST* scarce assets in the metaverse is at odds with the abundance of accellerating computing resources - so, for instance, selling access to virtual land is probably not something we need to model, except as it is useful as an abstract token for some other resource than virtual land - and trying to monopolize virtual land in and of itself is a fools game.