I'm in no way an artist or such, but just looking at the screens:
-less blur, blur makes everything bland and smooth, should be always avoided to me
-photoshop filters: they are EVIL. And Sharpen is no less evil
-the background could really use some more details and colours, it is too much tiled by now
-details! To me in good artworks, everything is there for a reason; just throwing a straight line won't cut it. For example the road isn't very blended on the background, it could be curvier, could have craters, sinks, cracks, tire tracks, etc.
Also the buildings would need much more details.
-and most important of all, lighting. everything in your world looks flat and dull, and it's difficult to tell from where the light comes. It definitely needs highlights + shading on 3D objects, and more contrast between them and the background!