What legal text should i include in my game?

Hi i an just about to publish my first game, but i’m unsure should what else should i include then just the text “Powered by cocos2dx” and who made the graphics and did the coding (in this case i did both);

My question is: “Can i use cocos2dx logo in my game in credits section? (and put address to cocos2d-x web page)?”