There are quite a few artifacts regarding shadows and lighting. Not really fixable without completely disabling the according shaders which makes the games quite ugly.
Unfortunately this gets more and more of an issue with newer deferred renderers that apply lighting (and more) in a second (2D) pass. 3D tech should have stopped at the level of DX9 engines a few years ago for injected 3D. ;) Z3D highly recommended for this one. Personally I played most of the game in 2D/Virtual Cinema.