I've heard that eastward uses 3d lighting (don't know how's that possible) and textures are affected by lights. But still they made sprites with some basic shadows and highlights. But I think I could get a good result by adding unity 2d lights on dark scene with little ambient lighting, making lights from custom Sprite shapes and animating them and then few Effects like bloom over it. I will also try adding basic normal maps like only 5 color map for (left, right, front, top and down) direction to test if looks better.
Thank you so much man! And cool extension BTW :)