with the perspective lines (such as those in the sidewalk) being opposite of the lines being created by the lightsource - it's freaking me out. It would probably benifit you if either you moved the perspective point to the left, or you moved the lightsource to the right. now i know there is no true perspective point since we're dealing with parallel lines here, but you get the point
for example - inside the garage, a shadow is being cast on the ground created by the wall. The line that it creates is the exact opposite of the lines on the sidewalk making it lose depth.
I'm also not too fond of the colours, but its in the same style as the original game, so i wont bother you there much.
Overall, this is a very solid work. I love the quality you put into everything. Great stuff - i wish we could see stuff like this more often here at pixelopolis. I still see some other things i'd like to give C+C on, but i'll have to go into depth a little later. I have to leave for work.
EDIT:
I'm not sure if my theory about the perspective thing is correct - but it's worth some expirimentation anyway. It seems to me that the lightsource in the original game is quite messed up itself. Somebody feel free to argue my point i made.