Insurgency: Sandstorm, the realistic military shooter, is free this weekend on Steam. After just releasing the yearly roadmap and a massive update of content and game modes, they are now letting everyone have a taste for free. I already own a copy of this modern shooter and can honestly say it is one of the best I have played in years. It is a great Co-Op first person shooter with an AI that is more than competent to give you a run for your money. So head on over to their Steam page and download your free weekend trail.