private IEnumerator adaptiveDifficultyChange() { while (!GameManager.gameOver) { yield return(GameManager.WaitForUnscaledSeconds(difficultyChangeDelay)); int HRdata = heartRate.getHeartRate(); if (HRdata > HRceiling) { changeDifficulty(adaptiveDifficultyFactor * -1); } else if (HRdata < HRceiling) { changeDifficulty(adaptiveDifficultyFactor); } } }