void OnTriggerEnter2D(Collider2D other)
    {
        //check, if gameobject has tag Moeda
        if (other.tag == "Moeda")
        {
//incrementar o nĂºmero de pontos
            pontos = pontos + 1;
            pointsSystem.AddPoint();
            //delete Moeda gameobject from the scene
            Destroy(other.gameObject);
        }
    }