As others have clearly stated before, his running could use some work. Considering you used a program that's so difficult to work with, and the difficulty of making a flash look this good in the first place, it's understandable, however, it just looked stiff to me. His knees never bent, not once during that entire running sequence. Furthermore, he held that gun while he ran as if he were aiming off in that direction without having to look. The barrel of his shotgun should have been pointed down by a few degrees, and he should have held the gun closer to his chest, not at arm's length like he was. You need his elbows to bend too, for that too happen.
With that out of the way, I have to congratulate you. In your comment, you clearly stated this facility was giant, and it does seem absolutely enormous. Also, the lighting and shading was exceptional, and I loved the way the screens reflected him so accurately, and how his visor reflected the screens so well. You did a wonderful job here. And that mysterious figure at the end... Oooh, the suspense is already building, sir. I cannot wait for the next installment in this (I'm guessing) series.
You do have an excellent future here, I must say.