Thanks for asking!
I think that the bigger problems related to some third party software that are used in Rope Run, so maybe they’re not Cocos2d-x-related problems per se. We find Cocos2d-x pretty easy to use, but some parts of the documentation could be better up-to-date, for example, we used experimental::AudioEngine to handle the audio, but it was quite difficult to find good examples about the usage.
This is a quite general answer, but we overcame these problems just by searching for more information, by trial and error, by brainstorming and by asking for help. Don’t be afraid to ask for help, but try to be as precise as possible and take your time to draft the question properly.
Other greater challenges that we faced concerned about creating the content for the game. Mainly, designing and developing all the levels and adjusting the difficulty level so that there’s a some kind of sense of the game gradually getting harder.