this is awesome, I would have never personally proposed this but it IS pretty damn interesting.
dodon pachi's shading basically seems to be surface angle coded to me.
meaning if it's vertical it's dark and the more horizontal it gets, the lighter it gets. that is the basic premise, a very simple premise.
Therefore to make it more eye catching, they use rimming and an astounding amount of bevels and extra detail on all surfaces, with some diferent colored lines and rims to top it off.
this is the reason height is so hard to tell within a single sprite, it is so marked in fact that they use projected shadows to show higher planes.
I must accept I say all this whitout having ever played the game

I am far more interested in the way they did the organic surfaces, I think the dirt textures are very convincing, and the ruinscapes I see in these screenshots are very well pulled off. HELM, what did you mean when you said they are not "efficiently tiled"?