code: function(entity, x, y){
              var tile = this.map.get(x, y);
              // if tile blocks movement
              if(!tile || !tile.passable){
                  return false;
              }
              return true;
          }
docs: Checks if an entity can move through a map tile.
  This does NOT check for entities on the tile blocking movement.
  This is where code for special cases changing an entity's ability to pass through a tile should be placed.
  Things like flying, swimming and ghosts moving through walls.
  @method entityCanMoveThrough
  @param {Entity} entity - The entity to check.
  @param {Number} x - The x map tile coord to check.
  @param {Number} y - The y map tile coord to check.
  @return {Bool}