its to beautiful for a TDM
basically this
for functional builds you really need to put away some of your urges to make it look good, and instead focus on the design.
right now i wouldn't see this as a very good tdm mainly because the actual gameplay would be taking place on the city streets/sidewalks, which is pretty much flat and offers little variation in gameplay. If I were you, I'd literally take a knife to the upper sections of all the skyscrapers above 1.5 or 1 64x64 cube(s) since they serve absolutely no purpose and nobody is really going to look up and criticize your build while they are playing.
you really should have focused more on the map design and terrain, rather than art. Like everyone else so far, I highly suggest (again) you to switch this over to a city build, rather than TDM.