Epic Games continues, from time to time, to provide free games through the new Epic Games Store platform. So, until April 18, 2019, you will be able to download The Witness game for free, a game developed by Thekla independent studio.
The Witness is a single player game focused on solving puzzles in an open world gaming environment. Players get to visit many locations and there are more than 500 puzzles to solve, each of them having original concepts.
The Witness can be downloaded for free from the Epic Games Store until April 18, 2010 by clicking on this link and then on the “free” button.