Overall it's a pretty good start, from this point on it depends what you're going for exactly. Is she supposed to be masculine? Her pose itself works fine, the temperament it conveys suits her character, resolute with a hint of her being some sort of a renegade princess. Obviously she belongs to a very western tradition of portraying heroines, with her tank top, relatively muscular arms, and overall realistic proportions, all of which suggesting guerrilla field experience and all kinds of strengthses already on the superficial level.
I don't know if you were intent on using her original in-game palette and/or how much of this still is w.i.p., but for a sprite this big I'd suggest a broader range of shades, less saturation as well as a lot less blue overall, a less plasticine like shading-style (I think you can loosen the invasiveness of the darks) and outlines to some extent (plus avoiding such close shades as the dark gray of the skin and the purple of her top next to each other, making them merge almost). Her eyes strike me as lifeless the way they are, kind of like the button-eyed people in coraline. Her feet and ankles could benefit from using references, especially the further leg has a very cylindrical ankle, but no heel and fails to suggest the weight it supports (could be a tad bigger as well, imo).
Cheers, solid start, keep it up!
