Cocos2D-x for Qt is a Qt port of the Cocos2d-x open-source C++ mobile 2D game framework, which is in turn a port from the original cocos2d-iphone project. The project aims to implement a feature-complete version for Qt supporting Symbian devices and Meego. There is good documentation on the wiki, including a porting guide and a tutorial for the JumpingGame example. A short video of JumpingGame is shown below: