Good concept. However, the image is really dark, not much color in the marbles, and the focus needs to be better. Perhaps some reflected light from a white board placed below the marbles and aiming up, out of camera sight, would have added just that little extra to get a nice sharp image with more color and focus.
Nice image. I love the mood. I wouldve liked to see the front three a little bit more in focus, but I know how difficult it is with marbles - had the same problem. Good shot nonethelss.