Tripwire Interactive announces the release of the free Heavy Metal Content Pack for Killing Floor, and they celebrate the news by offering a 10% discount on purchases of the co-op survival/horror game all week. The content pack adds two new weapons, the AK-47 and the Katana, along with a new map called KF-Foundry. The pack also adds new "on fire" behavior ("When you're on fire and running down the street, people get out of your way"), makes the flashlight more realistic, and addresses some bugs. The update is available automatically for free on Steam (where that 10% off sale is also underway), and the content pack will be part of the retail version of the game, which is due in North American and European stores soon. Full details are here.