anchor.diff:              tileH: 32,
               x: room_origin.x / 2,
               y: room_origin.y / 2,
  +            z: 1,
               type: SPRITE_TILES
           });
       };
  
positive.code: 
      Q.Sprite.extend("Player", {
          init: function(p) {
              p.z = 1; // player on TOP!
              p.sprite = "player";
              p.stepDistance = 24;
              p.stepDelay = 0.1;
  
negative.code:         init: function (p) {
              p.asset = '<%= asset_path("heart_blade.png") %>';
              p.type = SPRITE_TILES;
              p.z = 2;
  
              this._super(p);
          }
  