For your first imo this isn't that bad, I like how you worked out your depth, not everything is blurred but you have sections of it where you used bluring.

I think you could have played more with colour and lighting here, try and get the most out of it, that search light thingy in the sky would have been a good touch to brighten it up or add some kinda haze, the red in the far right would have been another place I would have jazzed up a bit. Also the white light coming from behind that broken thingy I would have made some look like broken rays of light to give it a more "shattered" kidna feel to this piece.

Danno what the whiteish effect is, maybe turn the colour so it's more blended with the ground ?

Good stuff man ^^ Keep pushin it, !