Bethesda's Dishonored puts you in the steampunk-style shoes of a disgraced royal bodyguard-turned-assassin. After being framed for the murder of the Empress, whom you were sworn to protect, you take up arms against those who were responsible for your fall from grace.
If the game world seems reminiscent of the Half-Life universe, that's because designers from developer Arkane Studios worked on Half-Life 2 once upon a time.
Though the trailer doesn't feature any gameplay, it does give you a sense of how the game will play. Much of the trailer is in first-person, like the main game, and shows off a game's mix of stealth, swordplay, and supernatural abilities like briefly stopping time.
Dishonored take to the streets in 2012.