Very, very nice, especially for a first. Detail is amazing.
I'd recommend sharpening it a bit though, because the basic scheme looks rather blurry as if it was made through soft brush smudging. But just so you don't over-sharpen it, make a new layer, go Image>Apply Image and Filter>Sharpen>Sharpen then soft erase (maybe on a low opacity) the parts that look over-sharpened. I think it would look a lot better more defined.
Also, I think it could look better if you extended the blue visor down a bit more, or maybe make it slightly less wide, I think it's a bit too rectangular as is.
But yeah, amazing work. The immense detail is teh secks. 9.25/10 :3