Haha some people have found that glitch, I just didn't clamp the head rotation so you can technically, at any point, flip your head 180 degrees and invert the world in that way. You basically just snapped ur own neck.
Too bad it's not really ur game but thanks for the honesty, I'd rather make something polarizing than too general I think. As for the environment, if you ever get up to making 3D games, its from an asset pack called eldorado. I only made the weapons, blubs, vendor, pipes & UI myself.