I like it! One thing I noticed almost immediately though are that the top pillar things are pillow shaded, and therefore don't agree with the light source you seem to be setting coming from the northwest corner. It would also be nice if the pillars cast shadows onto the ground as well. Color choice is quite nice.
Cool design, reminds me of one of the buildings from Doom 1 map (stage selection)
I'd suggest making the very bottom floor darker than the top one