public void Update(float dt)
        {
            if (HasWon || HasDied)
            {
                return;
            }

            bool hasWon = true;

            foreach (World w in Worlds)
            {
                if (w.HasDied)
                {
                    HasDied = true;
                    return;
                }

                // All worlds have to win before the level is complete
                if (!w.HasWon)
                {
                    hasWon = false;
                }
            }

            if (hasWon)
            {
                HasWon = true;
                return;
            }

            Worlds.ForEach(w => w.Update(dt));
        }
        public void Draw()
        {
            Worlds.ForEach(w => w.Draw());

            Game.GraphicsDevice.Viewport = Viewport;

            DrawBorders();
        }