private void OnCollisionEnter2D(Collision2D collision)
    {
        if (collision.gameObject.tag == "enemy")
        {
            AudioSource audio = GetComponent <AudioSource>();

            // audio.PlayOneShot(explode);

            audio.Play();

            rend.enabled = false;
            Destroy(gameObject, audio.clip.length);


            var Exp = Instantiate(explosion, gameObject.transform.position, Quaternion.identity);


            ui.ActivateGameOver();
        }
    }