Wow, this is stunning - I love the attention to details (reflections and shadows) - As it is, I like it, but I suggest making another version of this. I think that making the image more ominous would add more feeling to it - make it a little less sterile. Things I suggest - age the concrete a bit - grunge it up (I DO love that black and orange discoloration on the cement, upper right, towards the center), darken a sky a little - think pollution or a nuclear winter (a Fallout 3, Year Zero Remixed album cover, or 'The Road' kinda sky), darken the red light in the black spheres a bit - not too dark though (it's light after all), and maybe add some damage to the spheres - scratches, nicks, dings (how did they get there on this lonesome patch of concrete? Rolled? Dropped?). I do like this image very much as-is, but I think making a darker version, kinda post apocalyptic, would lend it a story and get viewers wondering just what happened in the world portrayed. Alien invasion? War? Well, this is my first critique - I hope you felt it was fair and constructive. I realize that it is not my art (making such beautiful images is beyond my skill level) so I'm not pretending that my input matters. Kudos - and, if you do make a darker version, I'd very much like to use it as a wallpaper.