IEnumerator Builder()
{
float t = 1.0f;
for (int i = 1; i < 500; i++)
{
yield return(new WaitForSeconds(Mathf.Max(Random.Range(0.8f, 4.0f) * t, 0.4f)));
grid.AddToRandomOnoccupiedBlock(Instantiate <GameObject>(blockPrefab));
t *= 0.995f;
}
SendMessageUpwards("Win");
}