Allow me to bend the rules a bit.
Xenoblade, Gundam Breaker and ANNO. It The first game would be a long sci-fi JRPG single player game that builds the world, establishes the lore and the characters then a sequel which would take place directly after the first game would be a MMORPG with a world 400 times as big as Xenoblade with real time strategy/base-building civilization sim elements and a real third person action mobile suit robot space warefare combat system for battling other players. Basically build your base and expand your empire, acquire more and better resources, develop newer technologies that build bigger, stronger and faster robots and weapons then fly your robots into space and battle other armies.
Also there would be monsters in the massive overworld you can grind with parties and online play in general being a big component, there would be questing, lesuire spots, massive world exploration and being able to build special custom bases anywhere you want in the world like minecraft, decorating and building all sorts of different kinds of buildings.
It would be fun in my opinion