Nintendo isn't making Mother 4 so a group of fans are. They've released a teaser trailer that promises a Winter 2014 release for their unofficial, fourth entry in the retro RPG series.
Like the previous Mother (a.k.a. Earthbound) games, Mother 4 is set in modern-day America. The game stars Travis, a young boy living in the sleepy town of Belring. He's forced to take a journey with three allies, including the leader of a biker gang. This team will have to face off against a mysterious group known as the Modern Men. The adventure will be comparable in length to other games in the series and will have connections to their storylines.
Everything about the trailer and screenshots screams Mother. The developers have done a great job of replicating the cartoonish, idealized America from the official series. The combat system looks very similar as well, with scrolling healthpoints, PSI and unusual enemies. They've even brought back the shady Hint Man.
The development team is also including a new soundtrack. You can find nine full songs on the game's website. Like the visuals of Mother 4, it's a very faithful recreation of the older games. The more I see about Mother 4, the more it feels like one big love letter to the series.
Mother 4's website stresses that the project isn't endorsed or authorized by Nintendo or series designer Shigesato Itoi. Hopefully their lawyers leave these fans alone, though. It's bad enough we had to wait years for Nintendo to re-release Mother 2 on modern consoles, and that we never got Mother 3. If Nintendo killed a new entry in the series, even an unofficial one, I'm not sure I'd forgive them.
The website mentions that they're not accepting any compensation for the game. It's not clear whether that means the game itself is free or if they're just not accepting development funding. It's entirely possible that the game will be available on launch for no charge, though, to prevent any legal action from Nintendo.
The developers plan to release Mother 4 as a standalone product on PC, Mac and Linux. No emulator will be necessary. There are currently no plans to port M4 to other platforms, which isn't surprising considering it's not-so-legal status.