Как правильно реализовать рестарт игры python?

есть готовая игра, но не удаеётся нормально реализовать выход\перезапуск. Подскажите как сделать, чтобы игра закрываалсь в любой момент на крестик, а во время проигрыша можно было либо возродиться, либо выйти?

import pygame
import time
import random

spd = 15

window_x = 720
window_y = 480

black = pygame.Color(0, 0, 0)
white = pygame.Color(255, 255, 255)
red = pygame.Color(255, 0, 0)
green = pygame.Color(0, 255, 0)
blue = pygame.Color(0, 0, 255)

pygame.init()

pygame.display.set_caption('"Змейка"©2022')
game_window = pygame.display.set_mode((window_x, window_y))

fps = pygame.time.Clock()

snake_position = [100, 50]

snake_body = [[100, 50],
              [90, 50],
              [80, 50],
              [70, 50]]

apple_position = [random.randrange(1, (window_x // 10)) * 10,
                  random.randrange(1, (window_y // 10)) * 10]

apple_spawn = True

direction = 'RIGHT'
change_to = direction

score = 0

def show_score(choice, color, font, size):
    score_font = pygame.font.SysFont('Courier New', size)
    score_surface = score_font.render('Счёт : ' + str(score), True, color)
    score_rect = score_surface.get_rect()
    game_window.blit(score_surface, score_rect)

def game_over():
    my_font = pygame.font.SysFont('Courier New', 30)
    game_over_surface = my_font.render(
        'Игра окончена. Счёт : ' + str(score), True, white)
    game_over_rect = game_over_surface.get_rect()
    game_over_rect.midtop = (window_x / 2, window_y / 4)
    game_window.blit(game_over_surface, game_over_rect)
    pygame.display.flip()
    time.sleep(2)
    quit()


while True:
    for event in pygame.event.get():
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                change_to = 'UP'
            if event.key == pygame.K_DOWN:
                change_to = 'DOWN'
            if event.key == pygame.K_LEFT:
                change_to = 'LEFT'
            if event.key == pygame.K_RIGHT:
                change_to = 'RIGHT'

    if change_to == 'UP' and direction != 'DOWN':
        direction = 'UP'
    if change_to == 'DOWN' and direction != 'UP':
        direction = 'DOWN'
    if change_to == 'LEFT' and direction != 'RIGHT':
        direction = 'LEFT'
    if change_to == 'RIGHT' and direction != 'LEFT':
        direction = 'RIGHT'

    if direction == 'UP':
        snake_position[1] -= 10
    if direction == 'DOWN':
        snake_position[1] += 10
    if direction == 'LEFT':
        snake_position[0] -= 10
    if direction == 'RIGHT':
        snake_position[0] += 10

    snake_body.insert(0, list(snake_position))
    if snake_position[0] == apple_position[0] and snake_position[1] == apple_position[1]:
        score += 1
        apple_spawn = False
    else:
        snake_body.pop()

    if not apple_spawn:
        apple_position = [random.randrange(1, (window_x // 10)) * 10,
                          random.randrange(1, (window_y // 10)) * 10]

    apple_spawn = True
    game_window.fill(black)

    for pos in snake_body:
        pygame.draw.rect(game_window, green,
                         pygame.Rect(pos[0], pos[1], 10, 10))

    pygame.draw.rect(game_window, red, pygame.Rect(
        apple_position[0], apple_position[1], 10, 10))

    if snake_position[0] < 0 or snake_position[0] > window_x - 10:
        game_over()
    if snake_position[1] < 0 or snake_position[1] > window_y - 10:
        game_over()

    for block in snake_body[1:]:
        if snake_position[0] == block[0] and snake_position[1] == block[1]:
            game_over()

    show_score(1, white, 'Courier New', 20)

    pygame.display.update()

    fps.tick(spd)