Thats awesome for your first, but the guy looks a bit squashed and if you dupe your text layer and set it to soft light and lower the opacity of it, it would blend in more. There's a tutorial about text somewhere in the GFX section.
But overall, I love it! Decent for your first sig and I can see the techniques you used ^_^
I cant really add anything to what loggeh said, i like the colours but get rid of the outer glow, maybe add some brushes in and some smudging? Basically blend the render more like loggeh said xD. Sorry i couldnt add more, but he pretty much summed it up.
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