Joining the C2 performance/rant
To put it simple, C2 is "Jack of all trades, master of none".
The good part is that more and more big companies are going for web apps (HTML5) ...The bad part is that no matter how much Ashley struggles, HTML5 will not even be close to native for at least 2-3 years ... Is still in "development". At least on mobiles where performance is weaker. While C2 has great HTML5 performance (simple games works decent even on 1GHz CPU and 512MB RAM), you can't compare it with native performance.
Like others said, a simple Crappy Fird clone takes 30MB and uses 20~40% CPU and still has some frame drops... Angry Bots (default demo of Unity) takes 38MB, uses around the same % of CPU, no frame drops.
Eli0s's Fancy Benchmark runs at 6~9 fps CPU 25~40% in Chrome, 8~9fps CPU 70~90% in FireFox on my Samsung Galaxy S4 while Epic Citadel runs at constant 60fps on default and 30~55fps at Ultra High Quality (rendered at 1080p), and Angry Bots mentioned above...
So yeah, "HTML5 has close to native performance" / sarcasm
Maybe the CPU part is close to native, but the graphics part is not even close. I've stressed my device to test Epic Citadel and Angry Bots at a lower framerate, and guess what, at 15~20fps they still look more fluid, with no stutter then C2 at 45~50fps
Just a quick remainder that Unity also started to support HTML5 and works quite well (on PC), on mobile is not optimized at the moment ... I know that the grass looks greener on the other side, but in most of cases it is greener
So yeah, the same old rant But all of us were aware (or should had been) when chosen to work with C2