I think there’s some clashing ideas here. It seems like it’s supposed to be an overgrown city, but then there’s the rock which makes it seem more remote. Otherwise it’s pretty good.
Everything is jumbled and mismatched, most of the added details don’t make sense, and the whole thing feels like three sets were mashed together and plants were added. The best part of this is the interior, as it feels like it could actually be the inside of a refuge during apocalyptic times.
You should try minimizing the amount of non-LEGO trees and work on making the area around the zombie jungle feel more post-apocalypse to help with the overall quality.