public IEnumerator _GameOver(bool won)
{
if (gameOver)
{
yield break; //stop the coroutine if it has already been called
}
gameOver = true;
Debug.Log("game over - " + (won ? "win" : "lost"));
//delay 1.5 second before issuing a global gameover event
yield return(new WaitForSeconds(1.5f));
gameState = _GameState.GameOver;
TDS.GameOver(won);
}