Activation on GOG
So you've got a GOG game on your hands, but how do you activate this bad boy?
Oh, it's very simple:
Just go to GOG.com, scroll to the very bottom of the page and click on the "Redeem Code" button.
Enter your code and press "Continue"
Double-check if you're receiving the correct game and then press "Continue" again
Finally, smack that "Pay for your order now" button! Don't worry, you don't actually have to pay at this stage, so the price should be displayed as "FREE".
And there you have it, a GOG game is now on your account and ready to be played!