Transform and lighting and per-pixel shading never looked better than in this underwater scene. Watch closely and see how realistically the lighting on the creature changes as the light from above is both reflected and refracted. In wireframe mode, you can see just how complex the creature is.
A very impressive 3D demo that only uses 177 kb. From the makers of .kkrieger. It's a small application because all textures are generated into RAM using procedural generation techniques. It may be a small download but needs a decent computer to be able to run it.