But why reinvent the wheel? I think that the key to Flash's success is in its roots as an excellent, intuitive vector graphics editor called SmartSketch. (Way easier to use than Inkscape, IMO) They added animation to compete with Macromedia Shockwave in 1995, and the rest is the well known history of corporate greed and a victim of its own success.
The Flash IDE is still around, however (https://www.adobe.com/products/animate.html), but Adobe's giving it up at the end of 2020 :( I can only hope that they open source it.
A light, friendly version is Flash 5. It's available online (http://www.oldversion.com/windows/macromedia-flash-5-0), weighs in at a whopping 18 MB, and still works on Windows 10!
Anyway, Flash 5 Player .swf files can be exported as standalone .exe "Projectors". For example, the IDE tutorial one (https://www.sharhon.com/files/flash5test.exe) stands at 405 KB and still runs on Windows 10 as well. Surely it would be possible to wrap _real_ Flash projectors in a WebAssembly Windows NT emulator using a drag-and-drop webpage...and let the games begin.