Cradle is a sci-fi first-person-view quest designed for the player to explore the surrounding world. The story is built around the relations of the protagonist and a mechanical girl who by quirk of fate found themselves amidst the desert.
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