Черный экран Python Pygame

Когда запускаю программу, появляется просто чёрный экран, и ничего больше. Пробовал банально добавить фон, но все равно экран чёрный. Кстати, через какое-то время окно с Pygame зависает полностью, и пишет "python не отвечает" Код:

from pygame import *
from random import randint, random, uniform


bacteries = sprite.Group()
foods_small = sprite.Group()

clock = time.Clock()
FPS = 75
window = display.set_mode((1300, 920))
display.set_caption('LiveSim')



class BacterySprite(sprite.Sprite):
    def __init__(self,obj_image, obj_x, obj_y,obj_speed_multiplier,obj_size_multiplier,obj_energyavg, obj_energy):
        super().__init__()
        self.image = transform.scale(image.load(obj_image), (30,30))
        self.rect = self.image.get_rect()
        self.rect.x = obj_x
        self.rect.y = obj_y
        self.speed = obj_speed_multiplier
        self.size = obj_size_multiplier
        self.energyavg = obj_energyavg
        self.energy = obj_energy


class FoodSprite(sprite.Sprite):
    def __init__(self,food_image,food_x,food_y):
        super().__init__()
        self.image = transform.scale(image.load(food_image), (10,10))
        self.rect = self.image.get_rect()
        self.rect.x = food_x
        self.rect.y = food_y



class Bacteria(BacterySprite):
    def update(self):
        if self.energy > 5:

            min_speed = self.speed - 0.15
            max_speed = self.speed + 0.15

            min_size = self.size - 0.15
            max_size = self.size + 0.15

            min_energyavg = self.energyavg - 0.15
            max_energyavg = self.energyavg + 0.15

            min_energy = self.energy - 0.15
            max_energy = self.energy + 0.15

            bacteria = Bacteria('bacteria.png', self.rect.x, self.rect.y, uniform(min_speed, max_speed), uniform(min_size, max_size), uniform(min_energyavg, max_energyavg), uniform(min_energy, max_energy))
            bacteries.add(bacteria)
            self.energy -= 3
        while self.energy >= 0.05:
            pass
class FoodSmall(FoodSprite):
    def update(self):
        pass
        




#параметры для бактерий и создание пяти "первенцов"

i = 0
for i in range(5):
    min_speed = 1 - 0.15
    max_speed = 1 + 0.15
    min_size = 1 - 0.15
    max_size = 1 + 0.15
    min_energyavg = 1 - 0.15
    max_energyavg = 1 + 0.15
    min_energy = 5 - 0.15
    max_energy = 5 + 0.15
    bacteria = Bacteria('bacteria.png', randint(10, 1250), 850, uniform(min_speed, max_speed), uniform(min_size, max_size), uniform(min_energyavg, max_energyavg), uniform(min_energy, max_energy))
    bacteries.add(bacteria)
    i+=1



food_allx = []
food_ally = []
#Создание еды!
i = 0
for i in range(30):
    foodadd_x = randint(5, 1200)
    food_allx.append(foodadd_x)

    foodadd_y = randint(5,800)
    food_ally.append(foodadd_y)

    food_s = FoodSmall('food_small.png', foodadd_x, foodadd_y)
    foods_small.add(food_s)
    i += 1

food_allx.sort()
food_ally.sort()




game = True
while game:
    for e in event.get():
        if e.type == QUIT:
            game = False
    collides = sprite.groupcollide(
            bacteries, foods_small, False, True
        )
    foods_small.update()
    foods_small.draw(window)
    bacteries.update()
    bacteries.draw(window)

    clock.tick(FPS)
    display.update()

Помогите, пожалуйста.