These offer truly general polygon based worlds. You can look in all directions. Levels are not restricted in geometry and they have nice lighting techniques. 3D Sprites also offer a lot more realistic creatures. Up to now sprites were always flat.
Lighting is still white only.
Sprites are used for monsters and other moving objects in games. In Crystal Space, the term sprites refers to the 3D Sprites which are actually real 3D objects. Unreal also offers very good AI for the creatures in its game. The creatures actually start acting reasonably smart. Curved surfaces are the next kid on the block.