nice. that perspective gives to look so big. 
blue highlights should be a bit yellow, because that soldier have a torch. it doesn't ? 
This reminds me of Superman #5 (pic here) of 1987, when Wonderwoman and Superman team up to face a bunch of huge robots and then discover a huge robot leader with glowing eyes under some ruins. And they're both like.... "shit." (For the record, I'm not some comic book guy with photographic memory, that's one of the few superhero comic books I was ever given as a boy)
Great work! I would like to have seen a bit more assymmetry in the closest tentacles in the background to break up the relative symmetry of the robot.
I like how you placed the highlights (except the pectoralis one maybe), very stylish. Colours are nice too.
Good piece. :)
Wow, nice atmosphere going on there!!!