Very nice figure and well done.
The next few lines are a few personal points and are not meant to distract from your work or be taken as criticism.
1.) Shading on the face is a bit to heavy for my liking.
2.) Stairs & column could use a bit more colour(darker) and more weathering.
3.) Gaps on the stairs are either too straight or not random enough, plus I feel a dark grey would have made a better groove colour(could be my monitor too).
Like I said I like it, but would have done a few things differently myself.
FYI, working on a few figs myself on the side (Fantasy & WW II).
This is my personal opinion of course, but than I tend to often work more on the backdrops than the figs/mecha that go into them.