docs: function(secs) {
      var states = game.controls.states;
  
      if (states.left) this.rotate(-Math.PI * secs);
      if (states.right) this.rotate(Math.PI * secs);
      if (states.front) this.walk(this.speed * secs);
      if (states.back) this.walk(-this.speed * secs);
    }