Wow. I wish I had even just half the talent of HTML/CSS/Javascript to pull something off of this calibre. I am really impressed, I can't wait to get my hands on this and deconstruct how they did it the best I can and play it too.
I'll just remain appreciating what these developers have been able to do from a distance until I can learn the basics myself. Programming these games is only half the work, it's the art direction, storyline and mechanics that make up the other 50% of the work to make a game in any language or framework.
The first produces html5 and abstracts a lot of the complexity of the low level that other approaches are based on. The second is more c++ oriented at this point. Hope it helps, or at least leads you to finding your own path to doing it. It also allows you to escape some of the js madness that happens when you interact with this stuff for browser output. It allowed me to get to a level of production that I could not imagine possible just by looking at the opengl stuff.