Ask HN: Replacement for Flash for interactive art websites

In the early 2000s, there was a plethora of "arty" websites that used a Flash frontend to deliver a non-traditional UI.

High-end graphic design websites like Praystation, The Square Root of -1, and many more I've forgotten, usually found from k10k.net.

Recently the Nintendo website y-n10.com was posted on HN and it gave me a hankering for that retro style, but Flash is no more.

Can anyone suggest a modern day replacement that will output HTML5 or similar? Bonus points if it has a desktop visual editor that imports SVG and images for animation, can play audio, and can easily be linked into backend APIs.