To get the free game, please be logged into indiegala in your browser (above giveaway page)..
you will find the giveaway box like below:
Simply close (x) the banner (no need to Like or Follow Indie Gala) and follow the instructions on that page to claim this giveaway (press the Claim Free Copy button). You will receive an email from IndieGala with instructions and your profile link or activation link (may require 60 minutes to 1 hour depending on traffic load), and following that link will get you to your Indie Gala profile page. Then go to My Profile>Bundles Library>IndieGala Giveaways>Terra Lander and press on the Steam button to get your free steam key.