Cocos Creator is a visual game creation system built over the Cocos2d-x game engine, enabling more visual development of 2D games. It is now available in public beta and can be downloaded here.
From the announcement:
Cocos Creator is a complete package of game development tools and workflow, including a game engine (based on Cocos2d-x), resource management, scene editing, game preview, debug and publish one project to multiple platforms.
Cocos Creator is an provides an innovative, easy to use toolset such as the UI system and Animation editor. The toolset will be expanding continuously and quickly, thanks to the open editor extension system.