HaxeFlixel is one of the most popular engines built on Lime/OpenFL but gives off no particular signal of its own. The best we can do is detect Lime/OpenFL.
Many Clickteam Fusion games are packaged as standalone executables with no supporting files.
We detect Construct games based on the presence of a particular JS file. However, it is possible to package all the content in a package.nw file, which hides this information from us and makes it indistinguishable from a generic Node.JS game. The best we can do for these missing cases is detect NodeJS.
It is possible to package a GameMaker game as a standalone executable with no supporting files, or only very generic ones.
Godot games can also be packaged as standalone executables with no external asset files.
Stencyl games don't always have recognizable files so it may not give any signal on it's own.
Twine games just have the same files as any other Chromium framework app.
Games using Havok SDK Suite (Physics, Cloth and AI) are usually don't have any special files for them, so we can not detect them.
It's built into Steam and game exe, so its can't be detected
Denuvo is built into exe, so it can not be detected either