I think your picture would have gained from some detail in the subjects. Since there is no forground/background for them to interact with in any way and the edges being so sharp, they seem a bit cut-out of the picture rather than being silhouettes.
I like the composition, Strong graphic. Too bad there's a merger with the distant fifures right arm with the nearer figure's left leg. Diagnal cloud patter very effective - paralleling the diagonal of the subjects.