Metal Gear Solid V: Ground Zeroes is currently available as a free download on Xbox 360 for Xbox Live Gold members. But very soon it won’t be. You have all day today and tomorrow to download the game before it returns to its full $20 price on October 16. Start your download on the Xbox Marketplace here.

Even if you don’t have an Xbox 360, you may want to pick Ground Zeroes up anyway, as it could one day be supported on Xbox One through backwards compatibility.

Ground Zeroes is free right now on Xbox 360 as part of Microsoft’s Games With Gold promotion. It will be replaced by Telltale’s The Walking Dead, starting on October 16.

Xbox One owners, meanwhile, can download a free copy of Valiant Hearts: The Great War all month long, while The Walking Dead will be free October 16-November 15.

Ground Zeroes was released in March 2014, earning an 8/10 score from GameSpot. Its follow-up, Metal Gear Solid V: The Phantom Pain, was released in September this year.