Civilization: Beyond Earth does have a demo, but it’s limited to 100 turns – not many to feel how a Civ game ticks. Given lukewarm responses to it, you might want to see more. Here’s your chance: the full game is free for everyone to play on Steam until Sunday evening. Saints Row IV is also running a free trial weekend but surely you already know whether you’d like to be a superpowered scamp flying around cyberspace and punching aliens. Both are on sale too.