Using Transform on instantiated objects

I have a prefab of a "tile" object. I've got code working to instantiate a series of these in a 10 x 10 grid. All of this works fine. When I hit play, it builds the grid as expected.

Before I was using Instantiate(), I'd written some code to rotate the tile by 90 degrees when clicked on. I assumed that when the objects were instantiated, that if I clicked on, for instance, the 2nd object on the far left from the bottom, that only that instance would get the Input.GetMouseButtonDown. However, nothing seems to happen when I click on any of the instances. What am I missing here? (Probably something basic, I am sure :/)

Here is the code in my script:

var tile : Transform; 

function Update () {
    if(Input.GetMouseButtonDown(0)) {
        transform.Rotate(0, 0, 90);
    }
}

function Awake() {
    for (var y = 0; y < 10; y++) {
        for (var x = 0; x < 10; x++) {
            var tile = Instantiate(tile, Vector3 (x*25, y*25, 0), Quaternion.identity);
        }
    }
}

Any help y'all could provide would be appreciated.

--Gray

Try replacing that with

function OnMouseDown () {
  transform.Rotate(0,0,90);
}