The destruction must be obviously placed perfectly. Notice that the brick effect on Blockland can be a toll on the brick count, but this cannot be dismissed. If you want the feel, you have to put destruction in the build many times. (Holes in the wall, broken windows, rubble, fire, smog/smoke.)
The bad factor is that terrain cannot be done unless it is specifically good well made. I would suggest using cubes. I really suggest talking to Phantom about terrain. Also, make your own trees in a huge varsity pack. Not huge but decent enough that you are not using the same 4 trees and placing them. Speaking of duplication, only do it correctly. Trees cannot be placed in a grid like fashion. Spread them out. (Apparently you already know this .-.)
You don't need to make every building accessible into the inside. Just make exteriors. Use black bricks and place them where windows are supposed to be if that house is suppose to just be there for aesthetics.
I would also like some screenshots of the current build. Just go on a screenshot spree and give them to me. I'll just give my suggestions.
(The build looks great so far, but the spawn lobby is meh.)