(seems to be a run on this topic the last couple of days) In addition to the suggestions about 1048 shadow map size, try some fun with the shadow cams. Using all spotlights, zoom & pan each light's Shadow Cam to cover only the part of the scene to be rendered. This will give you the highest-res shadows, but with very hard edges as you would get from the unobscured sun or other pinpoint light source. Zoom the shadow cams back out to feather & soften the shadow edges as desired. You might even consider using a cookie/gobo (i.e. a patterned transmap on a single sided square prop) in front of your key light to simulate sunlight/moonlight through leaves for a less sterile wall surface and hinting at depth & objects behind the camera. Wonderful concept with great details btw, -- but I think you are right, adjusting the flat lighting & adding some cast shadows for depth ought to make it even more interesting.