Having all your elements below the horizon line, really dulls the image. Inserting some big mountains with strong diagonal lines would increase the dynamics of your composition. GL.

The sky looks too realistic for the rest of the image.
if possible change the angle we are looking from or add more detail like greymval suggested!

Thanks guys I did a redo is this in the line of what you suggested

Looks cool, I would add some shadows under the robot guys. I think it would really help the image

nicely done

very cool work author

Thanks all I redid but to late to get it in