|Howdy from the Critique Club! :o)
You placed 32nd in the Hidden Faces challenge with this image, so there isn't a whole lot for me to say that you haven't already read from other commenters. I'll briefly touch on four aspects with my random thoughts...composition, technical details, relationship to challenge, and aesthetics.
1. Composition: I love the arrangement of the rocks. Perhaps the focal point (Mr. Rockenstein) could have been placed a bit off center, as a centered composition is not as pleasing to most DPC voter's eyes and is rather static.
2. Technical details: Your focus is sharp, the exposure is good, perhaps a little bit of dodging or curves adjustment could bring up some of the darker parts of the shot. I might even suggest a bit more sharpening to bring up some of the textures of the rocks. Aside from those nitpicks, it is visually interesting and appears to be shot well.
3. Relationship to challenge: You hit this one head-on (no pun intended). Excellent find and perfect for this challenge.
4. Aesthetics: It is a visually interesting and pleasing subject for the challenge. It is not a "cookie cutter" shot and that alone sets it apart from many others. It could have been stronger with more lighting adjustments, to emphasise his Frankenstein-ness or make it more macabre. However, that aside, it isn't a bad shot on the old eyes! :o)
Overall, it's a very strong image with good points and points upon which improvements could be made. Best of luck in future challenges, and if you have any questions, please feel free to PM me! :o)