The tooling has shifted from "decompilers" (which produce a .gmx or .yyp project file) to (which show you the assembly-like bytecode).
Older versions of GameMaker stored game data in a relatively unprotected manner. As analyst YellowAfterlife explains, "all game data was compressed and encrypted, but, in the end, stored without substantial post-processing". This made decompilation relatively straightforward. Tools existed that could take a GameMaker executable and reconstruct a valid source file, complete with original assets and code structure. gamemaker studio 2 decompiler
This guide is purely for educational and ethical purposes, such as analyzing your own compiled project for which you have the original source code, or for understanding the process in a controlled, non-infringing environment. The tooling has shifted from "decompilers" (which produce a
From a standard GMS2 Windows VM game, a decompiler can typically recover: This made decompilation relatively straightforward