CubeButton.js

var cubeToMove : CubeMover;

function Start() {
  cubeToMove = GameObject.Find("Mover").GetComponent(CubeMover);
}

function OnMouseDown () {
  transform.localScale.y = 0.2;
  cubeToMove.Move();
  cubeToMove.speed -= 0.1;
  
  // Debug.Log(  );
}

function OnMouseUp () {
  transform.localScale.y = 0.6;
}

CubeClicker.js

function OnMouseDrag () {
  SendMessage("Move", SendMessageOptions.DontRequireReceiver);
}

CubeMover.js

var speed : float = 5;

function Move () {
  transform.Translate(0, speed * Time.deltaTime, 0);
}