Basic pause menu code for Unity.

PauseMenu.cs

//************** REAL GAMES STUDIO ***************
//************************************************
//realgamesss.weebly.com
//gamejolt.com/@Real_Game
//realgamesss.newgrounds.com/
//real-games.itch.io/
//youtube.com/channel/UC_Adg-mo-IPg6uLacuQCZCQ
//************************************************

using UnityEngine;
 
public class PauseMenu : MonoBehaviour {
 
    public static bool GameIsPaused = false;
 
    public GameObject pauseMenuUI;
 
    void Update () {
        if (Input.GetKeyDown (KeyCode.Escape)) 
        {
            if (GameIsPaused) 
            {
                Resume();
            } else
            {
                Pause();
            }
        }    
    }
 
    public void Resume ()
    {
        pauseMenuUI.SetActive (false);
        Time.timeScale = 1f;
        GameIsPaused = false;
    }
 
    void Pause ()
    {
         pauseMenuUI.SetActive (true);
         Time.timeScale = 0f;
         GameIsPaused = true;
    }
 
    public void QuitGame()
    {
        Debug.Log ("Quiting game...");
        Application.Quit ();
    }
}