I always loved the window-simulator genre [1] of flash games as a kid, and it's no exaggeration to say that windows spoofs made me the person I am today. I wanted to make my own so badly that in middle school, I saved up to buy a student edition of Flash CS3 and spent a few years building "Window Doors" [2], which I'm proud to say was one of the most fully-featured windows spoofs of its time. Ten years later I have a cs/math degree, all thanks to the kind people on the Newgrounds BBS who were kind enough to put up with middle-school-me.
One identification of the keyword "pepperflashplugin-nonfree" and a browser restart later, I can wholeheartedly concur this implementation was very well made.
* https://www.newgrounds.com/portal/view/186896