My frog doesn't move but before i wrote the start and end part of the code it worked fine... can someone please help!

private bool gameStarted = false;
[SerializeField]
private Text gameStateText;
[SerializeField]
private GameObject player; 
[SerializeField]
private BirdMovment birdMovement;
[SerializeField]
private FollowCamera followCamera; 
private float restartDelay = 3f;
private float restartTimer;
private PlayerMovement playerMovement;
private PlayerHealth playerHealth; 

// Use this for initialization
void Start () {
    Cursor.visible = false;

    playerMovement = player.GetComponent<PlayerMovement> ();
    playerHealth = player.GetComponent<PlayerHealth> ();

    // Prevent the player moving at the start of the game
    playerMovement.enabled = false;

    // Prevent the bird moving at the start of the game 
    birdMovement.enabled = false;

    // Prevent the follow camera from moving to its game position 
    followCamera.enabled = false; 
}

// Update is called once per frame
void Update () {
    // If the game is not started and the player presses the space bar...
    if (gameStarted == false && Input.GetKeyUp (KeyCode.Space)) {

        //...start the game.
        StartGame();
    }

    // If the player is no longer alive...
    if (playerHealth.alive == false) {

        //...end the game
        EndGame ();

        // ...Increment a timer to count up to restarting...
        restartTimer = restartTimer + Time.deltaTime;

        // ...and if it reaches the restart delay...
        if (restartTimer >= restartDelay) {

            //...then reload the currently loaded level. 
            Application.LoadLevel (Application.loadedLevel);
    }

}

    private void StartGame () {

        // Set the game state 
        gameStarted = true;

        // Remove the start text 
        gameStateText.color = Color.clear;

        // Allow the bird to move 
        birdMovement.enabled = true;

        //Allow the camera to move
        followCamera.enabled = true;
    }


    private void EndGame () {

        // Set the game state 
        gameStarted = false;

        // Show the game over text 
        gameStateText.color = Color.white;
        gameStateText.text = "Game Over!";

        // Remove the player from the game 
        player.SetActive (false);

}