Sonic CB(Crystal Ball) is a fan-game experiment which blends 2D and 3D elements. The visuals are created by taking a large 3D sphere and wrapping it around the player. Other visual elements include a flexible screen which can zoom, stretch, and pan to the left or right. Objects on the 2D plane also have the ability to move along the Z-axis.
Promo video for Sonic CB v2.0.