This is a wonderful picture. Maybe not perfect for the challenge it was presented in, but great none the less. The overexposure really makes me recall those sunny days of summer when everything was so exciting and fresh and fun. You captured the expressions really well. It's amazing how you got so much information in them considering the overexposure. Just so I don't feel like a hypocrite, I gave you a 4 for the challenge.
Pro: Clever idea and some brilliant colors. Con: Too many totally washed out hot spots, and the yellows and grees especially seem way overexposed or over brightened.
I think, perhaps, if the faces were cropped out the feet would play a more central role, creatively. However, as it is, they really aren't the focal point of this shot. I like the high-key, contrasty approach.