https://www.pcgamer.com/get-xenonauts-free-in-gogs-summer-gaming-sale/

GOG's Summer Gaming Sale—or #SummerGaming Sale as it's stylised on-site—is live now through June 18. To mark the occasion, the digital storefront is giving away sci-fi strategy game Xenonauts free-of-charge from today through Wednesday, June 6 at 6am PST / 2pm BST.  

First, let's talk deals. I like D-Pad Studio's retro-styled platformer Owlboy, which, at 40 percent off, costs £10.69/$14.99. I'm also fond of Fallout: New Vegas, the best of the post-apocalyptic role-playing series, whose Ultimate Edition comes in at £7.49/$10.59, 50 percent less its recommended retail value.