Hello Mr. Skutnik, I'm a long term fan. I know you are working on Submachine Legacy but I want to share an Idea I have for multiplatform compatibility for your current collection.
There is an open source program called Ruffle and it plans to be a replacement for Adobe Flash Player. Not only does it restore Flash on web browsers, but also has stand alone programs for Windows, Mac, and Linux. It is incomplete currently, but enough support seems to have been done for your submachine games to work in it, although have not thoroughly tested them.
Maybe you could use that instead to have more compatibility with other Operating Systems?