Well, i believe the textures look ok, if your going for that "cubic" sorta sci-fi thing, but if you are, i suggest making a ceiling that compliments the cubic textures, instead of the open sky. The open sky from the pictures seems to look very unnatural in this setting and that aspect is not very pleasing to the eye. Also if you do make a ceiling, i think it would look best with openings to see the sky , and sky should be the orange sky or the current sky, though the majority of the map should be indoors. Just my thoughts from the screen shots.
-Cusoman