At a glance
Killing Floor has a Mac version: Steam sells it for macOS. The Mac requirements list only Intel: on Apple Silicon Rosetta 2 runs it, and old Mac versions sometimes do not start on current macOS. Try it in Steam for Mac first.
Steamstore
single player, multiplayer, co-opmodes
Killing Floor came out on Steam on 14 May 2009, made by Tripwire Interactive.
What your Mac needs
The Mac requirements list only Intel.
Minimum macOS in the Steam requirements: 10.5.8.
How to play
Open Steam for Mac and install Killing Floor as usual.
If the Mac version will not start, you can install the Windows version through Uncork: download Uncork, sign in to Steam and install Killing Floor from there (2 GB). We have not tested it ourselves.
The Windows version through Uncork needs a Mac with Apple Silicon (M1 or newer).