reminds me of my apple 2e a bit (minus the fancy color text).
it will have some sandbox stuff like crafting, tile placement, trap construction.
and a lab, where you can make creatures
then other players try to steal your gold and die in your traps.
and you get their loot
but then maybe you get too much loot and word gets out and you attract more looters
the maps are downloaded from user-defined urls, so people can host worlds on their servers and link to the main world.
like one big world that can sprawl across the net.
possibly a few files on dropbox (for altered maps and chests of loot), or maybe a mesh network.