Gone Home is one of the 60+ titles in the Humble Monthly Trove, a bank of games that are available to all Humble Monthly (opens in new tab) subscribers. Occasionally, one of these games gets given away free for a limited time, and Gone Home's number has been called—you can download it here until May 5 (opens in new tab).
You'll need to login to your Humble Bundle account first, but after that you'll get a DRM-free copy of the game, meaning you'll be able to launch it directly from your desktop rather than going through a launcher.
In Gone Home, you explore a detailed house to learn about the lives of the people that lived there. It's more than five years old, but it's still worth playing because of its touching story: you can read our review from the time here (opens in new tab).