Trivia / Killing Floor

• Ascended Fanfic: Numerous well-made custom maps and at least one pack of custom weapons have been officially added to the game through patches.
• Development Gag:
  • Scattered around some of the maps are newspaper clippings that allow you to read the headlines. One such newspaper features the headline "SUSPECTED CULT" with an image of the Clot as it appeared in the original Unreal Tournament 2004 mod.
  • Speaking of which, quite a lot of assets are borrowed from that very mod, including textures and static meshes. These are present on many maps and can be placed in a map editor.
• Dummied Out:
  • The game has an incomplete-but-mostly-functional music player feature (likely left over from Unreal Tournament 2004). Giving it a hotkey (such as by editing the user.ini in Killing Floor's System folder, finding the line F11= or some other empty key and adding MusicMenu behind it) can allow you to use it anywhere in the game by pressing that hotkey.
  • There are also several cut voice lines from the Trader which were supposed to be played after the player enters the shop or stays there until there are only ten seconds before the next wave starts. Just like the music player listed above, the lines can be played through the hotkey after working around in the .ini file.
• Keep Circulating the Tapes: Killing Floor: Calamity, the spin-off for the infamous OUYA console, became no longer functional when the aforementioned console was discontinued. It has briefly been ported to the mobile devices before being taken off Google Play, effectively rendering the chances of getting it almost nonexistent.
• Official Fan-Submitted Content: A whole lot of official levels are fan submissions for mapping contest (KF-Waterworks, KF-Departed and KF-Wyre, among the few). Even the weapons had been subjected to this: the Summer Sideshow 2012 event introduced several new guns (MK23, FN FAL, M7A3 and M99 AMR), which themselves started as custom weapons with their own mutators.
• Prop Recycling: The tractor on KF-Farm is taken straight from Red Orchestra. And not just the tractor - the entire map has been borrowed from the same game (where it is named "Hedgehog"), along with many props and assets.
• What Could Have Been: Transit (both Survival and Objective modes) was supposed to have three unique soundtracks named KF_BlooddriveN, KF_Contamination and KF_Killphase, but they were eventually scrapped. Fortunately, they had been released following the game ceasing receiving any updates from the developers, as well as fixing the broken music glitch on the survival version of the level.