paradine
NW.js is (sadly) notoriously slow on OSX. This is an issue with NW.js, not C2 though. I didn't have all the Android devices with me right now to run the Benchmark test, but I did have some iOS devices which I tested through it's browsers. I should probably get an Apple Developers account one day to try this stuff out...
Chrome (HTML5)
Score : 7735
Avg FPS : 56.25
Avg CPU : 49.72%
Windows 8 (VM) running on MacBook Pro Retina (i-5 2014) NW.js
Score : 7044
Avg FPS : 53.25
Avg CPU : 56.79%
MacBook Pro Retina (i-5 2014) NW.js
Score : 5966
Avg FPS : 42.75
Avg CPU : 59.07%
Nexus 7 (2013) (Android 5.1.1)
Score : 4858
Avg FPS : 24
Avg CPU : 86.62%
iPad Air 2 (2014) (iOS 9.0.2) through Chrome as it crashed on Safari
Score : 4791
Avg FPS : 19.5
Avg CPU : 93.13%
iPhone 6s (2015) (iOS 9.0.2) through Dophin Browser
Score : 5440
Avg FPS : 30.2
Avg CPU : 89.7%