BioShock: The Collection
https://store.epicgames.com/en-US/bundles/bioshock-the-collection
Experience the award-winning BioShock series. Journey to the cities of Rapture and Columbia across BioShock Remastered, BioShock 2 Remastered, and BioShock Infinite: The Complete Edition, including all single-player add-on content.
ConflictCraft
https://freebies.indiegala.com/conflictcraft
ConflictCraft is a strategy title set in an alternate reality where you gain control of the battles against ISIS insurgency.
Drawn in cartoon style, birds eye view, war game, building bases and conquer territories
Resource management is a key part of this game
You have tanks, attack choppers, support helicopters, jets, and rocket launchers at your disposal
Need a game to play with your roommate?
Local multiplayer mode is also available in this game.
A boat load of freebies for Android and iOS posted a couple of days ago.
https://www.gog.com/forum/general/massive_giveaways_blog