Interesting interplay of different tonal qaulities. Lighting accentuates the texture in the skin nicely. Very sharp throughout. Perhaps a little busy but creative.
Untitled? Why not "United" instead? :) Lovely idea, although I feel your lighting a bit sharp, I'd prefer a bit more diffused lighting. A simple black background (without those white spots) would be nice, too. Alltogether I like your idea. Good luck!
Nice idea, execution, and arrangement, variation of skin tones. Nice duotone choice, but feels too midtone gray, consider brightening the levels to compensate.