I'm trying to stay away from shaders. I'm not using a standard 3D level. My visible level will consist of handrawn art. The art will will be textures that are mapped onto a series of parallel camera facing planes. However, given I want the shadows to interact with these flat surfaces, I will include some invisible collision/shadow geometry for the shadows to contour to. Think of the levels as hand drawn backdrops except they have actual 3D depth to them.

This is a standard issue 2.5D adventure game shadow method. Wintermute Engine does it, but I'm not using Wintermute because I don't have access to a realtime camera. I could achieve everything else I wanted in that engine except the realtime camera which I'd use to move the camera into and out of levels.