Ahh! more flashy inside. :)
So those things on the flashy website are made by HTML5, which I exactly don't know what it means but are great. No need to to install additional softwares like for the flash you need to download a flash player.
This website only requires you to have HTML5 supported web browser(new versions of Mozilla Firefox, Opera, Chrome, Safari, IE9). The best part is you can even run it on your mobile phones. Why it is that a best part? That means you can even play HTML5 games built for mobile phones. Anyway the performance in the HTML5 website directly depends on the browser you are using and having a better GPU(Graphics Processing Unit) also helps.
Think flash is still better ? Think again after viewing this website http://html5games.com/
https://demos.mozilla.org/
Get to know HTML 5 better:
http://en.wikipedia.org/wiki/Html5
http://www.html5rocks.com/
Meanwhile, Firefox 4 rocks. Mmm and Opera super rocks(hope \/,)