Fleet Script

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;
using UnityEngine.SceneManagement;

public class FleetScript : MonoBehaviour
{
    //how often does the fleet move
    public float moveTime = 2;
    //speed
    public float moveSpeed;
    //move counter
    int moveCounter = 0;
    //movement direction
    int moveDir;

    public bool gameRun;

    public TMP_Text endText;

    void Start()
    {
        moveDir = 1;
        StartGame();
    }

    void Update()
    {
        if(gameRun && transform.childCount == 0)
        {
            //If the game is still on and the fleet doesn't have aliens anymore we stop the game
            StopGame(true);
        }
        //resetting the game when the player presses R
        if (Input.GetKeyDown(KeyCode.R)) SceneManager.LoadScene(0);
    }

    public void StopGame(bool win)
    {
        //Stop the game and movement
        CancelInvoke("Move");
        gameRun = false;
        //Switch on the text and fill it appropriately
        endText.gameObject.SetActive(true);
        endText.text = win ? "You Win!" : "You Lose!";
    }

    public void StartGame()
    {
        //sterting calling a method with specified interval
        InvokeRepeating("Move", moveTime, moveTime);
        //starting the game and disabling the text
        gameRun = true;
        endText.gameObject.SetActive(false);
    }

    void Move()
    {
        //depending on the direction change the position
        transform.position += new Vector3(moveSpeed * moveDir, 0, 0);
        moveCounter += moveDir;

        //Move down if the counter goes above 4 or below -4
        if (moveCounter <= -4 || moveCounter >= 4)
        {
            moveDir *= -1;
            transform.position -= new Vector3(0, moveSpeed, 0);
        }
    }
}