I agree with CELS on the roughness of this image. I personally like the sky how it is..my only gripe is the ground, I think it could use some nice rocks/boulders for texture to seperate it from the sky more. Also I'm loving the colors.
This looks very nice, but feels a bit rushed. It's a bit hard to make heads or tails of the planet below. I'm not sure if I'm looking at clouds, tentacles, pink sand dunes or something else. It looks a bit rough.
To me it seems like the viewer is below the surface of water, looking up at the sky. Not sure if the effect is intentional, but I like it.