Gorgeous piece...I love the sketchy edges and the grittiness of the underlying linework. I'd definitely try to get her number...

PROS:
-I like how color palette was kept so small...I spot just three main colors (the red of the armor, the green-ish tan of the armor, and the orange of the visor) and you make them work together very well. The bright orange on top of the desaturated tones on the armor also draws attention to the face of the figure, which is wonderful. Good use of color all around.
-The shapes of the armor are very well defined, which is due to really good use of shadow and value changes. The figure also recedes into the background, which is excellent.
-I can never totally tell, but I feel like a lot was done with very few strokes, and light blending on top of them. The light and shadow shapes in the piece are very solid, and the contours of the figure are well represented.
-Those quick, rough little lines of highlight are just awesome.

CONS:
-The left breast is raised a bit above the right one...I'm not sure if this was done with perspective in mind or if she is just bending her waist a bit to the right. However, the left breast and the armor on her quadriceps are the only places that indicate any kind of perspective, if this was the intention (The tips of her wings are level with each other, as are her feet, knees, and hands, which indicates an oblique view of the figure). Even if she was bending her waist, as long as the wings are attached to her back, you would see this bend in the top of the wings and the shoulderpads.
-A little bit of texure on teh armor plates would have made this...then again, I don't think you could have done that in painter 9 D=

Uh...that's really all I can spot that I think is a bit off...and that's already being nitpicky...I assume this was done pretty quickly, and for the expressed purpose of showing proof of concept for game art.

Take this critique with a grain of salt, I sure as heck couldn't do a piece like this.

Great job!

~Pan