GameManager.cs

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;

[RequireComponent(typeof(SteamVR_LoadLevel))]
public class GameManager : MonoBehaviour {
    public int score;
    public int projectilesThrown;
    public bool countNumberOfProjsThrown = true;
    public int projectilesPerLevel = 5;
    public bool loadLevelScreenFade = false;
    private static int levelNum;

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
        if (countNumberOfProjsThrown)
        {
            if(projectilesThrown >= projectilesPerLevel)
            {
                projectilesPerLevel = 0; //prevents this code from firing multiple times
                levelNum++;
                if (loadLevelScreenFade)
                {
                    //will only work if naming convenction is Scene0, Scene1, etc (can be customized to own convention)
                    SteamVR_LoadLevel.Begin("Scene" + levelNum); 
                }
                else
                {
                    //instant scene load with no fade
                    SceneManager.LoadScene(levelNum);
                }
            }
        }
	
	}

    public void CountProjectiles()
    {
        projectilesThrown++;
    }
}