Here is an example I can think of off the top of my head: https://www.youtube.com/watch?v=4Z2Z23SAFVA http://uploads.ungrounded.net/558000/558516_dotdotdot.swf?12...
I remember learning a lot of Flash and ActionScript using decompliers; you could see the code, assets, all sorts of fun stuff almost like view source in the web browser. Can't do that in video, thankfully we can in HTML5 but inspection of code isn't straight forward for more intense games yet.
EDIT: Looks like they've been uploaded to Youtube: https://www.youtube.com/user/homestarrunnerdotcom
Edit: huh, it kinda runs with Mozilla's Flash-runtime replacement, Shumway. Another few rounds of bugfixes and we might not need any Adobe code to play these files just as they are.
Supporting even one of them in its entirety is a Herculean effort. Supporting both is insane.
All their content was produced in Flash as at the time, it really was the only suitable delivery mechanism.