Dual Universe was an intriguing prospect when I first came across it on the PAX West floor. The game is already set for a Pre-Alpha release on September 30th, but developer Novaquark decided to bring it to the convention to give people an opportunity to mess around with the mechanics and explore the worlds they've built.
Dual Universe is essentially an MMO where you can build practically anything that you'd like. The goal of the devs is to create "the first virtual online civilization", and have done so by giving you the tools to mess with the environment by collecting everything you need from the planet's resources and building what you need from a massive template of objects. What's more, the world itself is expansive and fully changeable, meaning you could theoretically burrow your way from one side to the other with enough time. There is a moon and a gigantic space station orbiting the planet, both are visitable and can be tampered with. This game basically feels like Garry's Mod on speed. If you enjoy this kind of experience, I recommend checking out the mod as soon as possible.