"Level Up" was a named content patch released for Killing Floor released on 22 October 2009. It was previewed in an article on IGN two days before its release. There was also a three-day free weekend period for starting from the patches release date.
The Level Up content pack featured a redone interface, the addition of the Demolition perk, three weapons specific to the Demolitions perk; Pipe bombs, the M79 grenade launcher, and the M32 grenade launcher. The patch also featured the additional weapons: SCARMK17, M14 EBR, AA12, MP7M medic gun, a specimen; the Husk, and three maps; Wyre, Bedlam and Waterworks; the winner of the first Grindhouse map-making competition.