Think you’ve killed enough orcs? Think again! Return to the dead world beyond the rifts and conquer a new series of challenging fortresses under siege by the orc mob. In Orcs Must Die! – Lost Adventures you’ll travel from the depths of the Pit to the narrow passages high over the Great Gorge.
Open the Steam client, login and locate the Games tab on the top menu. Click this and then select “Activate a Product on Steam…”
Enter your unique code that's displayed on the 'Orders' page of CDKeys.com and follow the prompts to activate.
Your game is now viewable in the “Library” tab and is available to download/install when you’re ready. You can find additional support for the Steam client here: https://help.steampowered.com/en/wizard/HelpWithSteam