Awesome!
Have you thought about using background set-ups or dio stuff for scenery?
I do that sort of stuff in my comics, but I didn't in the animation for a few reasons. Simpler backgrounds gave me greater freedom as I was able to move the walls around depending on the shot I needed to take. Also, I was afraid that if I had any background items like crates or anything, I might accidentally touch them and then I'd end up having motion in the background where there wasn't supposed to be any, as has happened to me before in some other shorts.
That being said, I don't really like the empty look of the backgrounds. I guess it adds to the suspense and makes the Cobra facility seems more ominous with nothing but tall blank walls and no trash or anything lying around...