Hello again. I have posted another update, and finally understood the core of the problem.
Due to how I misunderstood the content delivery system, it appears I tried to combine some elements of the Windows and Linux builds to make transferring this rather tiny game much easier. Little did I know, some of these files I though were similar between the builds were not so similar after all.
This caused the initial launch version of the game to only work on Linux and not Windows, and the later build to work on Windows, but not Linux.
With this latest patch, I have resolved the issue of the Windows and Steam/Linux versions.
With the fix of the Linux version, I am also hoping to get an official "Deck Verified" status soon.
I apologize for the inconvenience, but I am thankful that it's things like this that help me understand how things work, so I don't make this mistake for future, and more serious projects.