given the pivot, the hat should also turn. The hat (beret?) needs reworking anyway, it's lightsource is unclear. (it's pretty close though, maybe 4 pixels are misplaced.)
(Rolland from Street Fighter Alpha has a beret and their sprites are similarly lit to this one, so you could use that as a hint for how to shade the beret.)

. Animationwise, the torso's fine.
the legs and boots move in the right way, but the shading jumps around..
The two key frames (at the beginning of the swing, and at the end) are perfectly shaded.. it's just the inbetween shading that is problematic.
Getting the inbetween frames right is possibly one of the trickier parts of animation
Consider simplifying the shading on the legs of the non-key frames until you get it animating smoothly. say, only use every second shade.. then add some shades back carefully once it's animating smoothly.
Rated 4 + fav. It'll be 5 if you fix the issues I mentioned.

It's 6 frames. =P

Good (not as good as the idle sprite, if you know what I mean). Nice shading. 5/5

Looks great. Very reminicent of the kof style. Theres only a few problems that need to be worked out though. First, her left foot never changes sizes after she turns and punches. The reflection of light on the left foot also just stays there and never moves. Another thing is that when she is punching to her full extent, the arm is rather short than it is in her idle stance. Just elongate the arm a bit, and mess with the left foot, and you can go ahead and call it quits for the day. Well, at least for me....Great job

Skit, that's exactly what I'm going to do ;P

Awesome! You should make a game outta these..

There is fine! When will appear game?

If you added a whip to this, it would just scream castlevania... but it doesn't have one, so I'll just have to point ot the obvious: this kicks some serious ass. The one really noticeable flaw I see is the way the left foot turns. When it transitions from one pose to another, it looks a little bit too abrupt. You might want to make a transition of the foot moving from forward to sideways in one of the existing frames or something. Still, other than that minor bit, this looks pretty pro. Good job.