It's good that you're motivated enough to tackle all these projects. However, before you work on a fighting game in particular, your "big" pixel art skills are going to need some work. There are a couple of major problems hindering these piece, and thankfully, they're both pretty simple to fix.
The first problem is the pose. You were right to feel odd about the arms and the legs. His body parts aren't working in unison to do anything meaningful. What's the purpose of the sprite? Is it going to be a walking animation, or an idle animation? His pose makes him look like his knees are pressed together with his lower legs splayed outward, butt sticking out. I'm also not quite sure why one of his arms is raised. I would suggest redoing the piece with a solid pose in mind; maybe use a mirror to come up with something. If you do that, then suddenly things will begin to make more sense and he won't look "odd" anymore.
The second problem is your chaotic pixel placement. It looks like you tried to imitate jpeg artifacts by hand. On small pieces like this (even though it may be bigger than your regular work), it's still important not to overcomplicate things. Here is an edit I made to illustrate:
It's good to illustrate texture, but you need to be subtle because you don't have very much room to do so in pixel art. If you go overboard it just looks like a murky swamp of random pixels. For now I think you'd be better off just picking a light source and shading from the opposite direction.
I hope this was helpful. Good luck with your games!
