void OnEnable()
        {
            if (instance && instance != this)
            {
                Debug.LogError("Multiple Game Controllers detected");
            }
            else
            {
                instance = this;
            }


            upperColor     = new LinkedLerp.MaterialColor("_BG_GRAD_COL_1", Color.white, 1, backgroundMaterial);
            middleColor    = new LinkedLerp.MaterialColor("_BG_CENTER_COL", Color.white, 1, backgroundMaterial);
            bottomColor    = new LinkedLerp.MaterialColor("_BG_GRAD_COL_2", Color.white, 1, backgroundMaterial);
            gradientMiddle = new LinkedLerp.MaterialFloat("_Center", 0.1f, 1, m: backgroundMaterial);

            if (Application.isPlaying)
            {
                OpenMainMenu_Internal();
                gameProgressData.Load();
            }
        }