I don't know & I don't care. IMHO video is the killer-app that made Flash a must-have everywhere. When it's down to games, Flash is a nice-to-have like Shockwave ended up being.
Oh SHIT. That game alone makes the case for HTML5 as far as I'm concerned. It may not be the most technically advanced HTML5 game I've seen (or is it?), but it's actually the kind of UI I'd want to use and that's more important than technical sophistication and fancy complex algorithms.
My life is over.
WARNING: Do not click unless you don't have anything better to do... I think I lost a month of my life to freeciv.