Playing with marbles!by 
RfariasComment by RiderGal: Critique Club
This is a pretty cool picture, because when I first saw it I thought it was pool balls.  I really like the large marbles, whether that is done with macro, or they really are larger.
Composition - Nice job with your composition, I like the fact that you don't have the cluster of marbles centered, but off to the side.  I might have tried cropping just a little more to bring your focus more onto the marbles.
Exposure - Good exposure, no complaints here.
Color - excellent use of color which really makes this photo eyecatching
Focus - excellent focus on the marble that is at a standstill.  Very nice job with that!
Background - the background is the low point for me on this picture.  I think it would have looked better with a solid background.  Also there are dust and scratches all over the background, which is destracting.  
Fit for challenge - perfect, really shows motion!  You have the stand still and the ones in movement, I think it's an excellent picture for the challenge.
Lighting - the lighting could have been slightly different as there is a severe hot spots on the marble standing still.  Also not sure if this is purposeful or not, but the right side is much darker then the left.
Wowability - pretty cool... makes you wonder what happened in the game.  
Final comments - very nice job, I personally would have you placed higher in this competition.  but great job on meeting the challenge and getting a pretty good picture at the same time!