@ Kuares: Looks pretty good to me so far. The only issue with it is it's sort of confusing how Fox and the Arwing are mashed against each other. It might help the Arwing fade into the background a little more if you used lighter, duller colors on it so it looks like it's far away. Fox's shoulder seems to be coming from his ear, so some planning of the basic body position could help before getting into details. I dunno, it's probably hard to draw on something as cramped as a 3DS screen though. You could create a more defined light source with where your highlights and shadows are placed. There's a bright area behind him on the left so you could make all of the surfaces that are turned toward the opposite direction much darker for a more dynamic look.
The 3ds app isn't that bad considering it's been my method of digitaldrawing for quite a while. It's got a color wheel, so that's not a limitation(atleast in the final product).A 3ds ap eh? not bad at all. Proportions are a tad wonkey but it's nothing crippling. He's got a cool line of action working for him so it makes up for a lot. The colors are nice and clean, and I like how you outlined sections with a darker color of their container, but overall the color selection feels a bit flat. I don't know how limited the 3ds ap is so I can't strike you down too hard in case they only provide like 32 colors or something.
The arwing is porbably the weakest part, mostly because it looks to me like the perspective is a tad off, and the lines could be straighter to make it look more hard surface.
Also, consider your silhouettes when making an action pose. Limbs in the wrong place can be distracting or look weird, even if they're in a place that is technically accurate. Fox's gun is hard to see because it's a similar color to his jacket, and the detail of both objects tangents a bit, making the gun hard to pick out, even if I know it's there. As a rule of thumb, make the pose completely recognizable even in a pure silhouetted form. If you filled your pose with black, does it still make sense? If it does, it's a really good pose.
Thanks for the critique, I'll work on it this weekend and bring it back later.