The thing that jumped out is that your human anatomy is off,check out that guy's down facing arm!(looks like its been attached wrong!)
Here some cut and paste critques from the sticky thread,they can be applied to your artwork.
Originally Posted by Bai Fan
Last edited by Artimatum; July 10th, 2012 at 05:40 PM.
A smooth sea never made a skillful sailor.
Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so."