This image has just punched me in the face with its pure awesomeness.
Holy crap dude, this is amazing. My favorite comic book character combined with one of my favorite video-game series.
And aside from my fangasm from the image, I have to give you major props for the very detailed armor that is true to both Halo and Captain America. It's not just Mjolnir armor painted red, white and blue, it's immediately recognizable as Captain America.