For Call of Duty: United Offensive on the Macintosh, GameFAQs has game information and a community message board for game discussion. With GameGator, you are able to compare deals across verified and trusted stores to find the cheapest Call of Duty: United Offensive Key for a fair price. All stores currently listed have to undergo very specific testing to ensure that customer support, game deliveries, and the game keys themselves are of the highest quality. 5aje.