I went through and did a few things. Small changes.
First, used the Burn/Dodge tool to darken (burn) the bright edge of his stomach. Also lightened (dodge) the edge of his shoulder closest to the sun. Neither looks great

See the first image below.
Then I duplicated the layer and on the duplicate, did a gaussian blur of 5px. Set that layer mode to Screen and lower the opacity to 20-30%. This lightens the image and makes it a little softer. See the second image below.
Finally, I did a gradient map on it. This helps to subtly balance colors if you don't over do it, which I always do. His green skin kind of glowed and I thought needed a little balance. See the third image below.
A gradient map changes colors to match the gradient you select. If you chose FG to BG gradient, the gradient map will use your FG color on the darker colors of your image and the BG color will replace the lighter colors on your image (I think). If you use one of the other gradients (like french flag or iridescent, etc) it will replace the colors of your image with those of the gradient.
Always do this on a duplicate layer because that layer mode (overlay, screen, etc) will be changed to whatever makes the main image look better. Usually the opacity has to be lowered as well.
Choose your gradient and FG/BG colors if necessary and then go Colors > Map > Gradient Map
Since I had two layers, I did "new from visible" (instead of duplicate) which made a new layer with all the stuff I'd already done. I tried using Iridescent as the gradient map, which made the image a little more red. I liked it but it made his skin less green. I did a light green/light yellow FG to BG gradient map and it made the light areas yellow and the dark areas green. I set the layer on Overlay and lowered the opacity to 15%.
It's a very small change, even smaller than using iridescent as the gradient map, but there you go.
dodge/burn > soften > gradient map > original



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Taking the image, modifying it and re-uploading has affected the quality of it. *sad face*