Fits the challenge but uninteresting composition and lighting is too harsh for my tastes. Try using the rule of thirds to spice it up and finding a place where the lighting is more diffuse.
I think it is too bright. The sunlit portion is over-saturated IMHO.
Also, I think a better effect would have taken the shot in the morning or evening to cast the shadow. Looks like it was taken around noon.
The highlights are blown and the compositon is too centered. Try a different time of day when the Sun isn't straight overhead and from a more creative angle.
Wow, the top half of that ball is really hot. If this is something you don't want, I recomend using a white reflector on the shadow side of the ball, and expose for the highlight.
I like "ball full of circles" idea. The bright side of the ball is a little bright, but I know how difficult that can be to rectify in the open challenges -- I've struggled with it myself.
overexposed too much. Subject is boring when it's so small within a frame and centered. Try the rule of thirds and place the ball off-center next time.