Source for Pong

enemyScore.cs

using UnityEngine;
using System.Collections;

public class enemyScore : MonoBehaviour {

  public static int scoreEnemy = 0;

	void OnCollisionEnter(Collision collision ){
	
		playerscore.scorePlayer = playerscore.scorePlayer + 1;
		keepScore.reset();
		
	}

}

keepScore.cs

using UnityEngine;
using System.Collections;

public class keepScore : MonoBehaviour {



  void Start(){
		DontDestroyOnLoad(transform.gameObject);
	}

	void Update(){
		if(playerscore.scorePlayer == 9){
			victory("player");
		}

		else if(enemyScore.scoreEnemy == 9){
			victory("enemy");
		}
	}

	public void victory(string winner){

		if(winner == "player"){
			Debug.Log("Player Wins");
			Application.LoadLevel("PlayerVictory");
		}

		else if(winner == "enemy"){
			Debug.Log("Enemy Wins");
			Application.LoadLevel("EnemyVictory");
		}
	}

	public static void reset(){
		
		Application.LoadLevel("pong");
	}
}

playerScore.cs

using UnityEngine;
using System.Collections;

public class playerscore : MonoBehaviour {

  public static int scorePlayer = 0;

	void OnCollisionEnter(Collision collision){
		
		enemyScore.scoreEnemy = enemyScore.scoreEnemy + 1;
		keepScore.reset();
		
	}

}

scoreGui.cs

using UnityEngine;
using System.Collections;

public class scoreGui : MonoBehaviour {
  void Start(){
		DontDestroyOnLoad(transform.gameObject);
	}
	// Update is called once per frame
	void OnGUI() {
		GUI.Label(new Rect(10, 10, 100, 20), playerscore.scorePlayer + " vs " + enemyScore.scoreEnemy);
	}
}