I would love to play a good MMORPG based on A Link to the Past. It's kind of pathetic how nostalgic I get for my clearly well-spent youth when I think about that game.
Well I make no promises about the 'good' part (in fact it seems like its modern incarnation is a complete mess) but Graal Online used to be MMORPG based on a link to the past-like engine, I think at one point back in the day it even had ripped sprites/tiles from LTTP.
