Today, Obsidian Entertainment launched a 30-minute playable demo of its upcoming survival action game Grounded. The catch is that only fans who are registered to be an Xbox Insider will have the opportunity to explore the vast, beautiful, and dangerous world of Grounded, so go ahead and remedy that if you're interested but aren't an Insider just yet. Then, you can get your hands on the 30-minute single-player demo, which is also available through Steam as part of the Steam Game Festival. (Full details about the demo can be viewed on Xbox Wire here.) The …