Note: I can't get the image to show up for some reason, but there is the link at the bottom. Can anyone tell me what I am doing wrong there?? : )
Here's some color notes if you are interested. I saw you had a cooler foreground so I spread that around your shadow area. I eliminated a lot of contrast in the shadow tones and simplified the shapes in the shadow. Then I added a warmer light to the scene and put some fairly saturated orange around the characters cast shadow to draw some attention there. Also, I added a warm hue to the transition area between the lights and darks. That's a place you can add color to to make a scene illuminate a bit more. I do the same thing when figure painting. Just saturate that area between shadow and light and it makes it pop so much more.
I just did it quick, so the marks are rough, but maybe it is something that you can use. : )
![] (https://www.flickr.com/photos/134396465@N04/18719517933/in/datetaken/lightbox/)