For all its gore-drenched mayhem, I’m starting to think that Tripwire’s co-op FPS Killing Floor 2 might not be the most serious of games. Maybe it’s the ridiculous steampunk hats and vengeful zombie clowns that gave it away? Either way, the game just launched its big summer event, and it’s bringing a lot of chunky new (and entirely free) content to the game, including a steampunk airship map which plays host to an all-new game mode. Oh, and Claudia Black voices a playable character now. Y’know – her from Firefly.