Buy Assassin's Creed: Liberation HD

For Steam CD Keys, you must download (HERE), install the Steam software and create a new account. If you already have a Steam account, once you log in, click "Add a game" (located in the bottom left corner), and then "Activate a Product on Steam". After a few more clicks, you will be prompted to type in your game code. Thus, the game will be activated and automatically added to your account library.

Uplay is Ubisoft's Download Platform. If you still don't have the client, you can download it HERE, install it, and create a Uplay account if you don't have one already. Then you will have to get the Download Manager related to your game, unzip its content and use the .exe file which will download your game. At last, once the download is over, you just have to get back on Uplay where you will see your games cover and click it to activate your CDKey.

Use your code on the Xbox Live network to activate your games or increase your Xbox Live account's credit. To access the Xbox Live network, you need the Xbox One, a broadband connexion, a Xbox Live account, and a storage device according to your console: Hard disk drive, memory card, or USB drive.

Use your gamecard Microsoft Points in the Xbox Live Marketplace of your Xbox 360 to purchase full games, rent the latest movies in High Definition, add downloadable content to your games. Exploit the full potential of Xbox Live!
To access the Xbox Live Marketplace, you need the following components and services: Xbox 360 Console, broadband internet connection, Xbox Live Silver membership (included in the product contents of the Xbox 360 entertainment system), Microsoft Passport account, Hard Disk or Memory Unit for the Xbox 360 Console.