I’m currently writing a story that involved a MMORPG, but it’s loosely related. Like, overlord style story. The MC basically started a guild, but since she couldn’t get anyone to join, she made NPCs to fill the slots…and that guild got pulled into a different world.
That MMORPG—granted, it was a product of imagination—basically had the sci fi, modern era, and fantasy elements all combined into a single world.
Well, too be honest, it’s very unlikely MMORPG with that kind of freedom will come out anytime soon. MMORPG that is combat oriented are generally more popular. RPGs with freedom tend to only be that, non MMO.