I'm going to be brutally honest here. C2 is the easiest development kit I have ever worked with, but the export features that it promises on the main site are more or less half-truths.
C2 relies on external wrappers to export, and almost all of them have compatibility issues with C2's exported code. For example, CocoonJS apps written in the CocoonJS SDK seem to perform very well, whereas C2-exported code that is run under CocoonJS struggles with things like physics.
This is most evident in the fact that over time, performance with CocoonJS using C2-created programs has gotten worse. I wouldn't be surprised if Ludei announced over the next few weeks that they are dropping support for C2, because this is what it seems like they are doing. Every new update they post promises new features, enhancements, and performance improvements, and recently every new update has resulted in C2 programs losing performance.