After the events of Batman: Arkham Asylum (2009), a section of the city of Gotham has been turned into a prison, designed to keep the scum of the city away from the people. Bruce Wayne protests this prison but is shortly kidnapped by the despicable Hugo Strange, thus having to face the city's most powerful villains as the Batman while trying to uncover Strange's plans.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 “MY GAMES” tab and start downloading.