C# Script error

using UnityEngine;
using UnityEngine.UI;

public class GameState : MonoBehaviour {
    private bool gameStarted = false;
    [SerializeField]
    private Text gameStateText;

    [SerializeField]
    private GameObject player;
    [SerializeField]
    private BirdMovement birdMovment;
    [SerializeField]
    private FollowCamera followCamera;
    private float restartDelay = 3;
    private float restartTimer;
    private PlayerMovement playerMovment;
    private PlayerHealth playerHealth;
    private PlayerMovement playerMovement;

    // Use this for initialization
    void Start () {
        Cursor.visible = false;
        playerMovement = player.GetComponent<PlayerMovement>();
        playerHealth = player.GetComponent<PlayerHealth>();
        // Prevent the player from moving at the start of the game
        playerMovment.enabled = false;
        // Prevent the bird from moving at the start of the game
        birdMovment.enabled = false;
        // Prevent the Camera from moving to its game position
        followCamera.enabled = false;
    }

    // Update is called once per frame
    void Update () {
        // If the Game has not started And the player has pressed the space bar...
        if (gameStarted == false && Input.GetKeyUp (KeyCode.Space))
        {
            StartGame();
        }
        // if the player is not alive...
        if (playerHealth.alive == false)
        {
            // end the game...
            EndGame();

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


            // and if it reaches the restart Delay...
            if (restartTimer >= restartDelay)
            {
                // reload the currently loaded level
                Application.LoadLevel (Application.loadedLevel);
            }
        }

    }
    private void StartGame
    {
        GameStarted = true();
        // Remove Start Text...

        gameStateText.color = Color.clear;

        // Allow the player to move...
        playerMovement.enabled = true;

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

        // allow the camera to move...
        followCamera.enabled = true;

    }
    private void EndGame
    {
        GameStarted = false;

        // Show the Gameover Text...
        gameStateText.enabled = Color.white;
        gameStateText.enabled = "Game over!"

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

    }
}