Here is a post from [TW]Wilsonam (VP, Tripwire Int)
Today we have released the free Heavy Metal Content Pack for Killing Floor AND we are throwing in a 10% discount on the game for the week. Following on from the success of the earlier DLC Character Pack, this entirely free update brings 2 new weapons, a brand new map and a bunch of other new features to the game. The major ones:
* 2 new weapons: the AK-47 assault rifle beefs up the Commando Perk, with heavier hitting power in semi and full automatic fire modes. The Katana is a classic melee weapon that combines speed, reach and cutting power.
* A brand new map: KF-Foundry. This map is set in a Horzine manufacturing facility, tucked away in an old steel foundry. Multiple levels, strange machinery and molten metal all serve to create an eerie and frantic location to fight off the specimen hordes!
Further new features include:
* Added "On Fire" behavior to all Specimens. When a specimen burns a certain amount, they will now freak out and behave like a burning zed should, making the flamethrower more effective.
* Updated the flashlight to look and act in a more realistic fashion.
* Added smoke to the Scrake's Chainsaw.
* Adjusted the spawning of the Patriarch boss character to prevent cases where the boss was spawning too close to players.
* Adjusted Bullpup's firing sound to have more bass.
* Adjusted "Crisp up" settings for some of the Specimens when on fire. Updated Mutator and Map White Lists (see the forums for more details)
And, of course, some bug fixes:
* Fixed Scrake's head glowing when decapitated.
* Fixed "The Long War", "The Hard War", and "The Completely Suicidal War" achievements not unlocking.
* Fixed known exploits on KF-Farm, KF-Manor, KF-Offices, and KF-WestLondon.