Above is another example of concept art from the 'Halo' gaming universe. This is a live-action drawing, that shows a real example of action in the game; including the soldiers in combat against their purple foe. It also brings more of the background, or setting into play. This helps further realize the potential product or experience that finished game will recreate in motion.
This is another interesting piece of concept art that I found online. I thought this one, better than any of the other ones, showed exactly what kind of environment the game wanted to compose of, along with creating a sense of emotional loneliness....which is interesting because most people wouldn't associate concept art as true finished art, when in reality, it may be the biggest piece of the puzzle.