That reflection...
...from the windows is fantastic! I'd wish you'd refine the details and brushstrokes on this one though. That mech to the left is just screaming "put bullet-whole and shrapnel-scratch details on me!!"
The water needs to be more distinguishable (Perhaps by adding some little waves and some reflections of the light-source to the left?). It took me some time to understand that it was water: at first it seemed like a vertical building with some dark mist around it.
This is just my very personal opinion.
9/10
4.5/5 => 5/5