public GameObject columnPrefab;
private Vector2 objectPoolPosition = new Vector2(0,900);
private float timeSinceLastSpawned;
public float spawnRate = 3f;
public GameObject SimpleObject;


void Start () {

    timeSinceLastSpawned = 0f;
//  InvokeRepeating ("InstantiateObject", 5f,2f);
}

public Transform target;

public float speed;
public void InstantiateObject()
{

    SimpleObject = (GameObject)Instantiate(columnPrefab, objectPoolPosition, Quaternion.identity);
    SimpleObject.transform.SetParent (GameObject.FindGameObjectWithTag("Canvas").transform, false);
}


void Update()
{
    timeSinceLastSpawned += Time.deltaTime;

    float step = speed * Time.deltaTime;
    if (timeSinceLastSpawned >= spawnRate) {

        InstantiateObject ();
        SimpleObject.transform.position = Vector3.MoveTowards (SimpleObject.transform.position, target.position, step);
        timeSinceLastSpawned = 0f;
    }
}