This...this brings a tear to my eyes, I actually read it with the same enthusiasm I had when i was reading the analysis on DOOM's graphics and optimization. 10/10 cured my ADHD.(I'm willing to wait for 7 years for a silksong level masterpiece).
That means a lot, thank you!
It's mostly all the code that has to be executed on the CPU that's the real issue. There are certain things that Game Maker is just very slow to compute, but I've got things running a lot faster after some rewriting and I'll also add in extra graphics settings like being able to turn down particle counts for really older machines.
Additionally, I'm looking into compiling the game in a different way using the YYC (YoYo Compiler) which can give a massive performance boost as it runs by reading the code natively versus being compiled into a Windows-specific build like it is currently.