The promised Killing Floor Summer Sideshow Event is now underway, offering new free Steampunk Character Pack DLC along with achievements for Tripwire Interactive's first-person shooter. In celebration, the game and all its paid DLC are on sale on Steam for half-off, as are Tripwire's other games, Dwarfs!? and The Ball, and there are Killing Floor and Dwarfs!? prizes for free in the Steam Summer Camp Prize Booth. Here's more:

But that isn't enough... so we have worked with our partners to bring you MORE free stuff. Teotl Studios have added a completely new Survival level for The Ball - free, of course. And Power of 2 have done their own Summer Event for Dwarfs!? - http://dwarfs-game.com/summerevent/. Now you can not only decorate all your Dwarfish caves with summer carnival paraphernalia - you also have a completely free mini-game to play as well. Play it well enough and you'll get to keep it after the summer event is over. And there are more achievements to go after!