Tripwire Interactive's hit co-op themed shooter Killing Floor continues to sell well and next week the developer plan to release an all new map pack for the game. The "Level Up" map pack will be free to download and will be released on October 22. Details about the map pack will be revealed on Tuesday.

But that's not all. Taking a cue from Valve and Epic who have offered free play weekends of their titles, Tripwire will also offer a free weekend of play for Killing Floor for anyone who hasn't checked the game out. The free play weekend will run from October 22 to October 25.