Good game, Very nice job!
I loved this game, it's different from alot of else's.
For your first flash game ever, well job. You have ALOT of potential in game making. Here are some tips you'd have to add to make it more sophisticated and more fun;
~Food, have to have food
~Fatique, don't take to much of this, else it would get very annoying. (For example, don't make him stop shooting and breathe heavily for a while when running out of energy, just make him shoot slower or something.)
~Longer/Harder storyline perhaps?
And maybe make a sequal ^_^
*Salutes* You disurve to be on the front page, my friend. Well done!