It's still a bit wonky to move around, but it's getting close to a playable state. Everything you see in the video is physics-based, there are no animations (the entire game is still less than 1 meg). The players are moved forward by the legs moving, not the other way around. The only "cheating" right now is forces applied to the waist for balance and direction. The gun recoil is simply a force applied to the gun, which moves the hand which then propagates the force through the body.