Injustice: Gods Among Us Game Keys

Go to: http://store.steampowered.com/ and download STEAM client
Click "Install Steam" (from the upper right corner)
Install and start application, login with your Account name and Password (create one if you don't have).
Please follow these instructions to activate a new retail purchase on Steam:
Launch Steam and log into your Steam account.
Click the Games Menu.
Choose Activate a Product on Steam...
Follow the onscreen instructions to complete the process.
After successful code verification go to the "LIBRARY" tab and start downloading.

Injustice: Gods Among Us Ultimate Edition enhances the bold new franchise to the fighting game genre from NetherRealm Studios. Featuring six new playable characters, over 30 new skins, and 60 new S. T. A. R. Labs missions, this edition packs a punch. In addition to DC Comics icons such as Batman, The Joker, Green Lantern, The Flash, Superman and Wonder Woman, the latest title from the award-winning studio presents a deep original story. Heroes and villains will engage in epic battles on a massive scale in a world where the line between good and evil has been blurred.