Lars Doucet, a Texas-based game developer is working with SteamDB to develop a tool that automatically detects the engine used in games on Steam. The tool is still in the very early phase of development, but it can detect the engine used in most games.
Besides the engine used by games, there is a bunch of other information that the tool discovers such as the SDK, Container, Emulator, and AntiCheat.
While the tool is not a hundred percent accurate and will probably never be due to some game engines being fundamentally undetectable, false negatives, and lack of script, the engine works to give a brief idea of the game engine used by Steam games.
In the current state of the technology, it’s detected that Unity is by far the most popular game engine used by 29235 games, followed by Unreal Engine with 7409. The most used SDK is NVIDIA PhysX and the popular AntiCheat is EasyAntiCheat followed by BattlEye.
How the tool works is, it runs a script on all the filenames for each Steam game’s all file depots. Using the info from the filename, the tool ascertains the findings. The tool is completely automatic and if you are interested in understanding the script, here is the link to GitHub.