Монети без UI

 Скрипт Life на Main Camera   (Screen.width, Screen.height)

    public static int a = 0;

    void OnGUI(){

        GUI.color = Color.yellow; 

        GUI.skin.box.fontSize = 34;

        GUI.Box(new Rect(0,0,200,50), "Монет: " + a);

    }

 Скрипт Coin на Монету  

    private string s = "";

    void OnTriggerEnter(Collider other)

    {

        if (s != gameObject.name)

        {

            Life.a++;

            s = gameObject.name;

            Destroy(gameObject);

        }

    }