I suggest you do a preview over wifi of your game if possible (cocoonJS can do that, I don't remember the procedure correctly though), with the debuger enabled (the url should be something like http://XX.XX.XX.XX:50000/debug )
The debuger could help you to see what is the problem
So the default cocoonjs debugger tells me a couple things, warnings, actions, errors. There is a profiler inside CocoonJS Launcher, but it only knows how to deal with native commands. So if you open up the logs from the launcher, it will be nothing but more low level api calls. See here: http://support.ludei.com/hc/en-us/articles/200767218-Profiling.
If you look at this image here
You will see the slices are great for telling me where the slow draws are, but they have no meaning to me in Construct 2.
In C2 I know "Fighting Methods", "Touch Methods for Puzzle".
I'm looking to get to that level.
Secondly, I am testing on slower phones, so my PC shows GPU/CPU always at like 0.1 - 4% max. That never translates to the phone equally.