I think a more extreme angle would have helped kick this up another notch. Also, maybe a little closer to the crab (either in the original shot, or in the crop). Finally, the focus on the crab is a little soft -- a touch of sharpen might help this particular image, but obviously better focus in the first place is even better. :-)
I like the idea. Quite blurry though. The crab should be more in focus. Could've aimed directly at the crab, pushed shutter halfway and locked focus, then pulled up to center, and then tripped the shutter. Just a suggestion.......