All this talk about C2 not being able to make larger complex games on mobiles... not true. I came to C2 with no former programming or art background.
My first game idea was a huge RPG at HD res (some would say its a mistake to aim big as a noob, I think learning as you go helps a lot), and I stumbled and learnt my way around. When it finished months later, it was 83MB, wouldn't even run with CocoonJS due to its limitations (which I wasn't aware of at the time, my fault!). By trimming it down and changing a lot of assets into PNG8 (which turns out looking 95-99% the same as PNG32), shortening the music loops, removing a few sprites and BG, it went down to 27MB, but still CocoonJS had trouble since it took 450MB of free ram due to it loading all assets into ram at the start. It would run on Tegra 3 devices at 25fps, I thought that was the limitation of HTML5 and accepted my fate.. but its not true, after more optimizations, it now runs on the the same device at 50-60 fps!
Even better recently with Crosswalk, max of 250MB ram required only. I am not saying my game is a great example of game development, polish, artistic sense or whatever (I had to trim a lot of the art and effects to get it to run well on mobiles). I am just saying its a huge game with over 3,600 events and it runs very well even on older mobiles (HTC Incredible S with a 1ghz Dual-Core and 512mb ram, 800x480 res).
See how busy the gameplay is:
Now its no Airscape or Penelope, but with being designed for mobiles and the limitations, there's no way you are going to get those games running smooth on older mobiles.
My current project is a massive space sci-fi sandbox!
Don't think such complex games are possible via html5/C2 on mobiles? I will prove its possible, alpha gameplay is already smooth on my Tegra 3.
My only gripes is the lack of AdMob and Google Store integration for C2/Intel XDK currently but its coming soon, something to look forward to when my current project is finished.
In summary, my opinion is that for smaller games, CocoonJS is actually fantastic for Android and iOS, but bigger games is where it falls flat on its face due to poor memory management, but its something Crosswalk can do (for Android only). Know the limitations and work within and around them.