The game is absolutely amazing! What a story, absolutely great!!!
But: Could you perhaps use a little bit more shader and color range? In its current state the characters look very doll-like. Plus, with less colors the 3D potential is very limited. It doesn't have to be HDR or animated of course but a bit more rendering would surely double or triple the gameplay experience. I can only imagine there is mass of content you already creatted, but I really think it could it be worth the effort.
For example, let's take Noel's hair: it really look yellow like straw. I can't help myself but finding yellow very strange for 3D VNs - usually blonde, light-colored blonde, gold or something like this is used, or in other words, it ranges by reflection of light.
Besides that, the game is perfect.