Okay, I've downloaded the app for the flash files you provided Baggrin, and I tried using it to run both the flash file and the version you archived, and yet I still get the same black screen from before with the Github code, link, whatever.
I am beginning to wonder if, despite being a newly bought computer, my computer itself is causing the issue. I was able to run it fine on my old laptop that I had for at least 5 years. I wouldn't even care if I had to start with a completely new game, I just want to get it to work because I enjoyed playing it.