The Signs

I think the landscapes look too artificial because the land is 100% flat and clean. The clouds look always bad in terragen (too streaky and plain) so maybe it would be a good idea to paint them or use photos you've taken instead? The planet in the sky however looks really good and gives a good massive feeling. What really looks excellent is the center image. It would look good just on it's own without the other pictures too. (don't care for the green box though)