Python - Ayuda Pygame "Class & Def Main"

import pygame

import sys

import random

from pygame import mixer

pygame.init()

WIDTH = 1200

HEIGHT = 720

screen = pygame.display.set_mode (((WIDTH, HEIGHT)), pygame.FULLSCREEN)

pygame.display.set_caption("Cyberpunk 2020 A New Dawn")

pygame.mouse.set_cursor((8,8),(0,0),(0,0,0,0,0,0,0,0),(0,0,0,0,0,0,0,0))

BLUE = (15, 150, 255)

PURPLE = (255, 150, 255)

ORANGE = (255, 155, 50)

MENU_1_IMAGE = pygame.image.load("Fondos/Background_01_720.png")

MENU_2_IMAGE = pygame.image.load("Fondos/Background_02_720.png")

BACKGROUND_IMAGE = pygame.image.load("Fondos/Background_03_720.png")

GAME_OVER_IMAGE = pygame.image.load("Fondos/Background_04_720.png")

PLAYER_IMAGE = pygame.image.load("Sprites/Player_02.png")

ENEMIES_IMAGE = pygame.image.load("Sprites/Enemy_02.png")

mixer.music.load("Sound/Menu_00.mp3")

mixer.music.play(-1)

Move_Sound = pygame.mixer.Sound("Sound/Audio/phaserUp5.ogg")

Collision_Sound = pygame.mixer.Sound("Sound/Audio/laser3.ogg")

Font_1 = pygame.font.Font("Fuentes/BLADRMF_.TTF", 20)

Font_2 = pygame.font.Font("Fuentes/BLADRMF_.TTF", 90)

Font_3 = pygame.font.Font("Fuentes/SwipeRaceDemo.ttf", 20)

Font_4 = pygame.font.Font("Fuentes/Miami.ttf", 25)

Font_5 = pygame.font.Font("Fuentes/Real Miami.ttf", 20)

enemy_size = 50

enemy_pos = [random.randint(0,WIDTH-enemy_size), 0]

enemy_list = [enemy_pos]

player_size = 50

player_pos = [WIDTH/2, 620]

SPEED = 10

clock = pygame.time.Clock()

score = 0

menu_1 = True

menu_2 = True

game_over = False

class player(pygame.sprite.Sprite):

        def __init__(self):

                super().__init__()

                self.PLAYER_IMAGE = pygame.image.load("Sprites/Player_02.png")

                self.player_size = 50

                self.player_pos = [WIDTH/2, 620]

def difficulty(score, SPEED):

	if score < 40:

		SPEED = 5

	elif score < 80:

		SPEED = 10

	elif score < 120:

		SPEED = 15

	else:

		SPEED = 20

	return SPEED

def draw_enemies(enemy_list):

	for enemy_pos in enemy_list:

		screen.blit(ENEMIES_IMAGE, (enemy_pos[0], enemy_pos[1], enemy_size, enemy_size))

def drop_enemies(enemy_list):

	delay = random.random()

	if len(enemy_list) < 8 and delay < 0.075:

		x_pos = random.randint(0,WIDTH-enemy_size)

		y_pos = 0

		enemy_list.append([x_pos, y_pos])

def update_enemies(enemy_list, score):

	for idx, enemy_pos in enumerate(enemy_list):

		if enemy_pos[1] >= 0 and enemy_pos[1] < HEIGHT:

			enemy_pos[1] += SPEED

		else:

			enemy_list.pop(idx)

			score += 1

	return score

def get_collision(player_pos, enemy_pos):

	p_x = player_pos[0]

	p_y = player_pos[1]

	e_x = enemy_pos[0]

	e_y = enemy_pos[1]

	if (e_x >= p_x and e_x < (p_x + player_size)) or (p_x >= e_x and p_x < (e_x + enemy_size)):

		if (e_y >= p_y and e_y < (p_y + player_size)) or (p_y >= e_y and p_y < (e_y + enemy_size)):

			return True

	return False

def collision_check(enemy_list, player_pos):

	for enemy_pos in enemy_list:

		if get_collision(enemy_pos, player_pos):

			return True

	return False

while menu_1:

        for event in pygame.event.get():

                if event.type == pygame.QUIT:

                        game_over = True

                        pygame.quit()

                if event.type == pygame.KEYDOWN:

                        if event.key == pygame.K_a:

                                Collision_Sound.play()

                                menu_1 = False

                if event.type == pygame.KEYDOWN:

                        if event.key == pygame.K_b:

                                game_over = True

                                pygame.quit()

        text_1 = "Cyberpunk"

        text_2 = "Press a to Play"

        text_3 = "Use the Arrow Keys to move"

        text_4 = "A Game by Alejandro Patino"

        text_5 = "A New Dawn"

        text_6 = "Press b to Exit"

        render_1 = Font_2.render(text_1, 1, ORANGE)

        render_2 = Font_3.render(text_2, 1, PURPLE)

        render_3 = Font_3.render(text_3, 1, BLUE)

        render_4 = Font_5.render(text_4, 1, PURPLE)

        render_5 = Font_3.render(text_5, 1, ORANGE)

        render_6 = Font_3.render(text_6, 1, ORANGE)

        screen.blit(MENU_1_IMAGE, [0,0])

        screen.blit(render_1, [WIDTH -920, HEIGHT -510])

        screen.blit(render_2, [WIDTH -835, HEIGHT -200])

        screen.blit(render_3, [WIDTH -1005, HEIGHT -170])

        screen.blit(render_4, [WIDTH -745, HEIGHT -60])

        screen.blit(render_5, [WIDTH -780, HEIGHT -420])

        screen.blit(render_6, [WIDTH -835, HEIGHT -140])

        pygame.display.flip()

while menu_2:

        for event in pygame.event.get():

                if event.type == pygame.QUIT:

                        game_over = True

                        pygame.quit()

                if event.type == pygame.KEYDOWN:

                        if event.key == pygame.K_a:

                                Collision_Sound.play()

                                menu_2 = False

        text_1 = "In a near future..."

        text_2 = "...the androids have taken over the cities..."

        text_3 = "...you can run..."

        text_4 = "...but there is no scape."

        text_5 = "Press A to Play"

        render_1 = Font_4.render(text_1, 1, ORANGE)

        render_2 = Font_4.render(text_2, 1, ORANGE)

        render_3 = Font_4.render(text_3, 1, ORANGE)

        render_4 = Font_4.render(text_4, 1, ORANGE)

        render_5 = Font_5.render(text_5, 1, PURPLE)

        screen.blit(MENU_2_IMAGE, [0,0])

        screen.blit(render_1, [WIDTH -940, HEIGHT -480])

        screen.blit(render_2, [WIDTH -950, HEIGHT -440])

        screen.blit(render_3, [WIDTH -940, HEIGHT -280])

        screen.blit(render_4, [WIDTH -940, HEIGHT -240])

        screen.blit(render_5, [WIDTH -220, HEIGHT -100])

        pygame.display.flip()

while not game_over:

	for event in pygame.event.get():

		if event.type == pygame.QUIT:

			sys.exit()

		if event.type == pygame.KEYDOWN:

			x = player_pos[0]

			y = player_pos[1]

			if event.key == pygame.K_LEFT:

				x -= 50

				Move_Sound.play()

			elif event.key == pygame.K_RIGHT:

				x += 50

				Move_Sound.play()

			player_pos = [x,y]

	drop_enemies(enemy_list)

	score = update_enemies(enemy_list, score)

	SPEED = difficulty(score, SPEED)

	text = "Score:" + str(score)

	render = Font_3.render(text, 1, PURPLE)

	screen.blit(BACKGROUND_IMAGE, [0,0])

	screen.blit(render, [WIDTH -1150, HEIGHT -35])

	screen.blit(PLAYER_IMAGE, [player_pos, player_pos])

	if collision_check(enemy_list, player_pos):

		game_over = True

		Collision_Sound.play()

		break

	draw_enemies(enemy_list)

	clock.tick(50)

	pygame.display.update()

if game_over:

    game_over = False

    while not game_over:

        for event in pygame.event.get():

                if event.type == pygame.QUIT:

                        game_over = True

                        pygame.quit()

                if event.type == pygame.KEYDOWN:

                        if event.key == pygame.K_b:

                                game_over = True

                                pygame.quit()

        text_1 = "Game Over"

        text_2 = "Press B to Exit Game"

        text_3 = "Thanks for Playing!"

        render_1 = Font_2.render(text_1, 1, PURPLE)

        render_2 = Font_3.render(text_2, 1, ORANGE)

        render_3 = Font_5.render(text_3, 1, BLUE)

        screen.blit(GAME_OVER_IMAGE, [0,0])

        screen.blit(render_1, [WIDTH -940, HEIGHT -600])

        screen.blit(render_2, [WIDTH -890, HEIGHT -100])

        screen.blit(render_3, [WIDTH -715, HEIGHT -510])

        pygame.display.flip()

    pygame.quit()

    sys.exit()