Nice image with lots of details. love it. I have some problems with it though. First, it feels a bit flat. Maybe it's the colours? If you know about colour theory you would know that orange/yellow is a complementary colour to the lilac/blue violet that you are using in you'r piece. I can see some orange in those metal thingies in the headpiece, but it's not really orange at all. It's just greys in between red and pink. So the image ends up feeling a bit... monotone? I don't know man... i'm not that good at this stuff myself so maybe i shouldn't try to give advice. And maybe a monotone look was what you were after.
Anyways, those galaxy marble things are pretty cool man, but i think you could have put a bit more detail on those. I did a quick paintover... i could post the link if you're interested.
It's still an epic piece, peace.