It's only an idea, but I am wondering if it is possible to accomplish this using Cocos2D, or if I would need a 3D engine.
A character in the center of a stage, looking downwards towards the ground. Enemies come in from all sides (front, back left, right). If the character were to rotate 180 degrees, so that it would be looking 'backwards', but the point of view would rotate also to look at the enemies behind.