Cocos2d-x VS Cocos2d-js

I’m a newbie trying to decide which game developing engine or framework (don’t know the appropriate term for it) is best for me to start making mobile games with. I have a little knowledge in javascript, and lots in HTML and CSS, but no C++ so going with javascript is probably the best route. I want to develop games for IOS, Android, and Windows and perhaps some apps too. So a few questions:

  1. Which has more features, cocos2d-x or cocos2d-js? Because I saw less features listed in the product page of cocos2d-js.

  2. Is the development environment of cocos2d-js web or native?

  3. I saw cocos2d-x also supports JavaScript so why would I go for cocos2d-js?

  4. Other engines I’m considering are, GameMaker Studio, Unity, App Game Kit. Any opinions about those compared to cocos2d?

Thanks.

It think it depends on what kind of game you want to make
cocos2d-js is tailored for quick and small game which can be published to web mobile
cocos2d-x is for mobile games which requires more performance.

And based on your experience, I would say js is the way to go.