From what I can tell, the Diorama and the GM were very nicely builts.
The Diorama's building, however seems to have some cracks on the roof, so I might fix that...
The Gm's pose is a bit strange... maybe giving it a pose with more "motion" will help it?
One more critique: The Gm and teh Diorama don't really go together convincingly. It just looks like the GM was placed on the diorama... I might add some weathering or some pigment to make it look like the GM had been running around in the dust. Moreover, The diorama doesn't really reflect a mecha walking through it.
