In general the last version of your charakter is ok (at least the stand frame). Although there are some big and lots of little things you can concentrate on, for this I also made you an edit to illustrate the points.
-color design: your charakter is pretty grey. It's at the moment no problem but if you are laying it in the background, it could be that your char gets lost. I usually prefer strong colors for my charakters to make them stand out. For example a electric blue hair will lead the players attention to the charakter.
-lighting: drawing (and spriting) is all about controlling forms. Once you are able to shade different objects in the right way you are also able to shade more complex forms like humans, hair and stuff. At the moment your shading is off at some places, especially at the arms and the hair.
-cleanness: especially if you are working at low resolutions with pixels it's very important to work very clean. Each pixel displays a roughly estimated 5x5cm piece of your charakter. THat's a pretty big areal. If there is one pixel off it can maybe cause problems. Also keep in mind that less is more. Make sure that your pixel clusters (pixel areas with the same color) have beautiful shapes and clean appeareances.
-dynamics: the general action line of your character is already pretty dynamic, but iit's important to show this also with the arms, the legs and the head. It could be tweaked a little
-shadow:a shadow sometimes helps to improve the spatial feeling of your drawings. If you can combine a shadow with your environments, do it. It helps tthe viewer to see how high a char is jumping or is he is running very fast and lots of other things.