I kinda like this photo. Did you saturate the green in the grass? The green seems to be running into the mud a bit. Still it is a beautiful shot, overall.
Needs better focus on the plate. Colors on the grass are a bit off. Good idea for the challenge, and the composition is decent. The chaulk mixed with the sand makes it look like hte game is just over.
I thought I commented on this earlier. It looks as though nothing is actually in focus in this one. The colours are cool and the angle is cool, but you need to have something in focus. Maybe try to create some drama with a narrow DOF.
Very good idea ... and surely illustrates the spirit of the challenge. As for technical consideration, focus to me looks soft, maybe it would have more impact if the focus was right on.