NFTWorlds is one of the interesting metaverse. Where the land is available for the gamers and the external minecraft servers. Where you once purchase the land that can be reused for game purpose. This is Ethereum blockchain based metaverse so the fees are kind of a problem but apart from that this can have some value like those mars land, sandbox type of the project. The NFT is available through opensea marketplace that you can buy and sell. You can check out the project: https://www.nftworlds.com/