Mother 4, which has been in development for quite a few years now, is a fanmade sequel to Mother 3, which is a sequel to Mother 2, also known as Earthbound, which was re-released in the U.S. last month.
We've been writing about Mother 4 for three years now, and the folks at Nintendo haven't sent in the lawyers yet. Hopefully they don't plan on changing their minds, because the game looks great. From the foreboding, trippy music to the isometric city streets, this looks like everything you could possibly want out of a new Mother game. And since Mother creator Shigesato Itoi has declared that he's done with the series, this might be the only Mother 4 we can possibly get.
While you wait for this one, you can check out Earthbound on the Wii U's Virtual Console.