Unknown Worlds and Epic Games have teamed up to offer Subnautica as a gift to you for free on PC inside the Epic Games store. You can login and download it right now! Subnautica, the Golden Joystick PC Game of the Year for 2018, is an underwater adventure set on an alien ocean planet where a massive, open world full of wonder and peril awaits you. Subnautica will be free to download until. Best of all, once you grab the game, it’s yours to keep!The Epic Games store will be offering a free game every two weeks until the end of 2019. The next free game, Super Meat Boy, will be available beginning Dec 28th.