On CDKeys.com you get Mafia III for 5,84 €.
Convert the currency to the upper right of the pound and use the 5% FaceBook coupon (to be redeemed you have to be logged in on CDKEYS.com).
It's 1968 and after years of combat in Vietnam, Lincoln Clay. Now back home in New Bordeaux, Lincoln is set on escaping a criminal past. But if you're a good friend, you'll be able to get a good deal of money. Intense gun fights, visceral hand-to-hand combat, white knuckle driving and street smarts wants all be needed. But with the right crew, tough decisions and some dirty hands, it's possible to make it to the top of the city's underworld.