NextLevel.cs

using UnityEngine;
using System.Collections;

public class NextLevel : MonoBehaviour {
    public GameObject player;
    public int checker = 0;

    void OnCollisionEnter2D(Collision2D col)
    {
        if (col.gameObject.tag == "Player")
        {
            checker = checker + 1;
            Debug.Log("HitExit");
            Application.LoadLevel(1);
        }
    }
}