void OnTriggerEnter2D(Collider2D col)
    {
        EnemyWeapon enemyMissile = col.GetComponent <EnemyWeapon>();

        if (enemyMissile)
        {
            health -= enemyMissile.GetDamage();
            enemyMissile.Hit();
            if (health <= 0)
            {
                Die();
            }
        }
    }