It's looking good so far. I hope you plan to do the lower part of his torso, because it would be even more impressive if you did.
As far as the shading, it's not really right. It looks like you shaded from the edge out, which is not good because it makes it look flat. Also, it looks like you used black and a neon green, when you should have started wit ha darker shade of green and worked on from there, then added highlights.
Everyone has different workflow, but usually sketch, cleanup base color, shading, in depth shading, highlights, selout is how i work when it comes to pixel art.
Keep it up though, would be cool to see the whole team up there.