Warhammer 40,000: Space Marine's first DLC, the Exterminatus pack, has just launched as a free download. The pack adds Exterminatus mode, which is basically Horde by another name, and as such smells every bit as sweet. Which, given that it's a bloody four-player throwdown against limitless waves of grunting space-cretins, probably isn't all that sweet at all, but it makes for fun times.