Level Unlock system

Hi all

kindly i need your support in my Unlock level system , i finlized the following steps :

first i built the UI as the following screen shoot :

then i use the LevelSelector script and its working fine as the followin screen shoot :

the LevelSelector script syntax code as the following :

using UnityEngine; using UnityEngine.UI; using UnityEngine.SceneManagement;

public class LevelSelector : MonoBehaviour {

 //public SceneFader fader;

 public Button[] levelButtons;

 void Start ()
 {
     int levelReached = PlayerPrefs.GetInt("levelReached", 1);

     for (int i = 0; i < levelButtons.Length; i++)
     {
         if (i + 1 > levelReached)
             levelButtons[i].interactable = false;
     }
 }

 public void changeToScene(int changeTheScene)
 {
     SceneManager.LoadScene(changeTheScene);
 }

}

then i used the enemy health manager as the following :

using UnityEngine; using System.Collections;

public class EnemyHealth :MonoBehaviour {

 public float curHealth;
 public float maxHealth;
 
 
 void Start () {
     
     curHealth=100f;
     maxHealth =100f;
     
 }
 
 void Update () {
     EHealthManager (0);
 }
 
 
 public    float EHealthManager(float f){
     
     if (curHealth > maxHealth)
         curHealth = maxHealth;
     
     if (curHealth < 0)
         curHealth = 0 ;
     
     if (maxHealth < 1)
         maxHealth = 1;
     curHealth += f;


     float modifiedHealth  = (curHealth / maxHealth) * 500;
     return modifiedHealth;

 }
 
 void OnGUI(){
     
     GUI.Box(new Rect(20,50,EHealthManager(0),25), ((int) curHealth).ToString() + "/" + ((int)maxHealth).ToString());
     
 }

}

then i use LevelManager script to unlock the next level "button2" as the following :

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

public class LevelManager : MonoBehaviour { public string nextLevel = "Level-2"; public int levelToUnlock = 2; public GameObject EnemyHealth;

 public void LoadNextLevel()
 {


     if(EnemyHealth.GetComponent<EnemyHealth>().curHealth /EnemyHealth.GetComponent<EnemyHealth>().maxHealth <= 0){
         

     int currentUnlock = PlayerPrefs.GetInt("levelReached");

     if (currentUnlock < levelToUnlock) {
         PlayerPrefs.SetInt("levelReached", levelToUnlock);
     }
     SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex + 1);
         PlayerPrefs.SetInt("SavedLevel1", 1);
         Debug.Log("SavedLeve1 = 1");

 

}

 }

}

my issues :

I need ( level manager script) doing the following : 1. If the player health less than zero restart the game that mean he lose to win 2. If the total enemy’s health less than zero , message you win then load next level 3. If the total enemy’s health less than zero unlock button level 2 4. Save all level status 5. how to restart the unlock system

appricated your kindy support to fix level manager script where i dont face any error but its not working ,