the work is good.
If anything I would suggest you sketch without a purpose. I noticed many more finished areas which could be a style choice I understand but the entire thought of the sketch didn't get fufilled. In your sketch think about attitude and stance. See if you can read your thoughts between the lines when you're done. You'll find that you will be able to recall the finest details about what was going on in your mind while you were sketching...that's the biggest thrill for me.
Keep it up...nice work.
-Lemorris