campfire/Assets/Scripts/GameOverMenu.cs

using UnityEngine;
using UnityEngine.SceneManagement;

[RequireComponent(typeof(CanvasGroup))]
public class GameOverMenu : MonoBehaviour {
    public GameState GameState;

    private CanvasGroup Canvas;

    private void Awake() {
        Canvas = GetComponent<CanvasGroup>();
        UpdateCanvas(true);
    }

    private void Update() {
        UpdateCanvas(false);
    }

    private void UpdateCanvas(bool instantTransition) {
        bool IsGameOver = GameState.Current == State.GameOver;
        Canvas.alpha = Mathf.Lerp(Canvas.alpha, IsGameOver ? 1 : 0, instantTransition ? 1 : 2f * Time.deltaTime);
        Canvas.blocksRaycasts = IsGameOver;
        Canvas.interactable = IsGameOver;
    }

    public void Replay() {
        SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex);
    }

    public void Exit() {
        Application.Quit();
    }
}