Wow It shows you had a pretty clear idea of volume all throughout the piece, since your shading was spot on in some places, specially the clothes, where even if the "technique" wasn't all that impressive (colors, but no textures) you really nailed areas that protruded in a 3D plane. Amazing, congrats.
before looking at the video i would have bet money that picture came from animation. But now it doesnt look so 3d after scoping how you done it. great work tho. how long did it really take?
