Nice! It reminds me of one of the Therian designs from the (sadly out of print) AT-43 miniatures game from Rackham, but with much more going on with the techno-details.
The combination of the outsized "gun arm" and "support legs" I find particularly interesting, as it gives me the impression of a robotic device intended for, say, support fire, and the semi-humanoid nature of the main body might be an afterthought (i.e., a standard modular robot chassis modified for a particular role), with high mobility being a low priority. I can envision the robot "bracing" itself, repositioning the legs for a shot (that is, if this sort of technology has any sort of "kick-back" when firing the weapon). The "hunchback" design and the almost skeletal nature of some of the pieces helps to convey a sense of menace, without going over the top about it.