Wow, this one is really good! Top-notch presentation, very cool concept, and great implementation. Impressive! The only issue I have with it is visibility: sometimes your character blends in too much with the environment, especially in the really dark areas. Also, on the arm itself, the lever used for firing is kinda hard to notice/distinguish, and it took me a while to figure it out even with the "Shoot" prompt.
Overall though, very good! One of my favourites so far. Great work!