Gonna kick things off with the most important issue. Performance. It's pretty bad. Even alone, on a local server my frame-rate in the city was simply too low. This won't be a easy fix. You simply need to figure out what detail you want to keep. What major buildings you might need to replace. It will not look as good. But this in the first place a video game, not a art gallery. Performance is very important
![Smile :)](./images/smilies/icon_e_smile.gif)
Ive you can squeeze out 10 extra frames or a bit more it should be nearly fine I hope. But right now I don't see how it's gonna be playable.
The atmosphere is amazing though. Lighting can be made a bit brighter though. It's quite too dark for the time of day you choose.
Fog settings aren't right. The fog cuts in too fast. Need to blend it out better.
Minimap is also too dark. And it doesn't go well with the super bright grid. Have to play with the opacity there a bit of the grid and just give it some more brightness.
Doesn't seem like you did lightmaps in 3dsmax, which is needed for final release as you got many custom buildings with no lightmap samples. Might also help you by optimizing them and saving some lightmap space.