Really nice use of the theme as a twist on a classic game. Slightly awkward to shift the grayscale with z/x/c when controlling with WASD meant that I wasn't changing them as frequently as I would have liked. As I was shooting with left-mouse maybe cycling through the greayscale with right-mouse would be a nice option to have. I also thought the difficulty could have ramped up just a bit faster, but other than that I liked it a lot.