The Epic Games Store is now offering free copies of Galactic Civilizations III for Windows as its latest weekly giveaway. Stardock's space strategy sequel is yours to keep as long as you snag a copy between now and next Thursday. At that point first-person puzzle game Relicta will take its place with a 100% discount. Here's a bit on GalCiv3:

What if one day, humans woke up to find that they weren’t alone in the galaxy? They make their way into space and discover other alien civilizations with their own histories and motivations looking to make a name for themselves. Choose your race - Human, Drengin, Altarian, and so many more - and lead your civilization into a golden age in one of the largest 4X strategy games ever made!

Research new technology, design starships, and colonize new worlds as you face threats and conquer challenges from new and mysterious sources. Negotiate trade and treaties, wage wars, spy on your enemies, and promote outstanding citizens. And when you've finished that, play again as one of the many included alien civilizations each with its own history, technology tree, ship components, and more.