Thanks to efforts by volunteers Nosamu and bai0, the Internet Archive's flash emulation just jumped generations ahead.

Mute/Unmute works. The screen resizes based on the actual animation's information. And for a certain group who will flip their lid:

We can do multi-swf flash now!

A pile of previously "broken" flashes will join the collection this week.

https://archive.org/details/softwarelibrary_flash