Good animation but criticism-wise I agree with JayG that it should be a bit faster and in my opinion should be more exaggerated, e.g. when he swings his arm back.
A demo reel... hmmm... I dont think you have enough work for a demo reel, one thing that I noticed is that all you have at the moment is animation... when the employer is looking at your demo reel they need to know you can do alot of things like modeling, texturing, particle systems maybe, e.c.t.
Here's a good link for demo reels:
http://www.animationmentor.com/webinar/ ... rlos1.htmlHope it helps