The creatures of ancient myths, legends and knowledge are real. Trapped for thousands of years inside the Pandora's Box, they await the day of liberation … Deckard, a thief hired to steal an ancestral artifact, inadvertently unleashes a war between man and myth.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.