Hi Matthew,
It's hard to crit cause you did a great job!
the only thing that i might add would be a few blinks
and some motion blur...
do you have control over the camera angle,
or how you frame your scene in this contest ?
Your animation is powerful, but maybe if the camera was closer to the character , or if you were looking at the character from a lower vantage point he would have more authority.
thanks for sharing
B)