This is quite cool, I downloaded it and checked it out for 15 minutes or so.
I liked the lighting, especially the sharp-ish spotlights casting onto buildings (like you see in the upper right of the first screenshot). A nice contrast and atmospheric. Detail was cool too, sufficient debris/trash all around, etc.
Minor things I didn't care for: the invisible barrier stopping you inside the tunnel, it'd have been nice if you blocked it off instead of using an invisible wall; the flashing light at the bus stop, a cool idea but it seemed too "regular" (on, off, on, off, on, off.. always at the same rate); I managed to get myself up the hill that I think I wasn't supposed to be able to, the one in the third picture. I just jumped up the displacement, somewhere towards the left. To be fair I spent a fair bit of time trying to do that (that's just me).
Regardless, a very nice, realistic environment for the most part; especially to hear you made it so quickly (half the map in a day? that's crazy).