Shady areas lifted nicely and sharpening efforts look good. I'm assuming the four central figures are the main subject, in which case I find the ones to the left and the tree trunk impact on the right somewhat distracting. Wondering if application of the "Darken/Lighten Centre" filter in NIK Color Efex might overcome this - I've found it a useful tool in these circumstances with a much more gentle impact than any of the vignette filters.