Not long ago, Playstation previewed their first original series, Powers. Now it's Xbox's turn, and they really went all out.
Halo: Nightfall takes place (obviously) in the Halo universe - following Agent Jameson Locke as he and his team travel to a Halo ring to confront the Covenant and stop them before they can release a compound designed to kill humans. And - as a sidenote - word has it Locke will eventually be a playable character in Halo 5.
The whole series will be available with the Halo: Master Chief Collection.
Also, for real - the assault rifles are perfect: