void saveStatistics()
    {
        stats.levelCompleted = true;
        bool ff = (stats.collectedFruits.Count == overallfruits);

        stats.hasAllFruits = ff;
        stats.hasCrystals  = crystalMan.allFound();

        string str = JsonUtility.ToJson(this.stats);

        PlayerPrefs.SetString(levelName() + "stats", str);
        int c = PlayerPrefs.GetInt("coins") + this.coins;

        PlayerPrefs.SetInt("coins", c);
        PlayerPrefs.Save();
    }