Didn't read the whole topic but from what i've seen from the poll it's not the same as the game I am suggesting.

Squeebs was a game I played very shortly but looks and play's like a very good game. It's a 2d sidescrolling MMORPG. Much like mario but then with everyone having their own champion/hero.

The game is long dead and no longer in development. What would be way better then any of the options shown right now is having city's that are already built.
Just standard towns that anyone can visit, with various shops and taverns. Let people team up in party's to go into an instanced zone wich only they can enter (5 people).

With it being 2d and sidescrolling it doesn't need a lot of graphics work.