Good idea and motion capture. I think the fully fallen dominos, while part of the story, are a visual distraction here. the blacks are so black, to me, they blend together and make a mass. I think a bit brighter background, and perhaps if you could have captured fewer dominos, starting with the fifth from the left, it would have been stronger for me.
I really like this, and the composition is perfect with the "quad' threes about to knock over the "double" threes. Perfect job on the background. I hope you ribbon.
great motion. the overall image seems noisy - perhaps underexposed. to get the motion, you must have had a slightly longer exposure though. dunno until I see your details, but based on what I see that is what I think.