This photo caught my eye while browsing. Something about the lighting almost gives an illusion effect to the footprints to make them look not indented, but comint out of the sand. I would take out the holes to the right. Other than that, I might bump a little contrast and color, but I really like the shot a lot just as it is also. Visually it's interesting, and the subjest makes you look twice.
Nice. A unique shot with a lot of visual interest. One suggestion I can make is to use all the image size available to you on challenge entries. If you had used the entire 640 pixels and 150k that a challenge allows, this shot would probably show a fair amount more detail. Non-challenge entries can be larger if you feel it is worth the storage space.