In my Opinion you missunderstood somethings about shaders...
The Shaders doesnt make your Level looks much more impressive without adding much more details...

So , your Game starts after an Nuclear Meltdown...okay cool...Abandoned City style... But your "ROOM" doesnt fit this style, it looks to much clean for this.
Search for Google Pictures for Tschernobyl and have a look inside the Houses, you see much more destroyed furniture / dirt / cracks a.s.o...

regards Sebastian

[Blender]Terrain creation ENG/GER
[Blender]Low Poly Tree Modeling
[GIMP]Create a Texture for Terrains