Dishonored

Dishonored is a stealth-based game set in an alternate world resembling Steampunk Victorian London, with gameplay resembling a mix of Thief, Deus Ex and BioShock (series), with an artstyle resembling Half-Life 2. You play as Corvo Attano, bodyguard to the Empress of the Isles, the land in which the game is set. Unfortunately, the Empress is killed by an unknown murderer at the beginning of the game. Corvo is framed by the corrupt Lord Regent and is set to be executed for the Empress' murder. While he is in prison, a deadly rat-born plague kills half of the population of the capital city of the Isles and the setting of the game, Dunwall. But before Corvo is executed, a mysterious supernatural being called The Outsider appears to Corvo and gifts him his Mark, granting Corvo the ability to use magical powers. Corvo escapes from prison and quickly joins a resistance movement as a Professional Killer in order to take revenge upon the Lord Regent and his corrupt and villainous government. Set to be released October 9, 2012.