้้้้i want to fixed movement in cube

i want to insert code for fix movement object object received input movement 1 step by 1 getkey
so object it move to point let get key again but i don't know how do it i need object move like table

using UnityEngine; using System.Collections;

public class ballcontrol : MonoBehaviour {

 void Update ()

 {
     if (Input.GetKey("up"))
         transform.Rotate (new Vector3 (2, 0, 0), Space.World);
     if (Input.GetKey("down"))
         transform.Rotate (new Vector3 (-2, 0, 0), Space.World);
     if (Input.GetKey("left"))
         transform.Rotate (new Vector3 (0, 0, -2), Space.World);
     if (Input.GetKey("right"))
         transform.Rotate (new Vector3 (0, 0, 2), Space.World);
 }
 

}