Roll a Ball in Unity3D with Script

using UnityEngine;
using UnityEngine.UI;
using System.Collections;

public class playerControl : MonoBehaviour {

    public float speed;
    public Text countText;
    public Text winText;

    private Rigidbody rb;
    private int count;

    void Start ()
    {
        rb = GetComponent<Rigidbody> ();
        count = 0;
        SetCountText ();
        winText.text = "";
    }
    void FixedUpdate ()
    {

        float moveHorizontal = Input.GetAxis ("Horizontal");
        float moveVertical = Input.GetAxis ("Vertical");
   
            Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);

            rb.AddForce (movement);
    }
    // Destroy everything that enters the trigger

    void OnTriggerEnter (Collider other)
    {
        if (other.gameObject.CompareTag ("pickup"))
        {
            other.gameObject.SetActive (false);
            count = count +1;
            SetCountText();
        }
    }
    void SetCountText()
    {
        countText.text = "Count: " + count.ToString ();
        if (count >= 13) {
            winText.text = "You Win!";
        }
    }
}