I’m trying to make it so that whenever the character hits the floor the game ends. I am only new to pygame and am trying to make this game without the use of following a tutorial step by step. I can’t find an answer anywhere online about my problem without having to completely redo my code. Any help would be appreciated. ps I know the code itself is probably horrible but I’ll get better as I learn more!

 import pygame 

 from sys import exit 

 class player(pygame.sprite.Sprite):
     def __init__(self):
         super().__init__()
         self.bird = pygame.image.load('bird.png').convert_alpha()
         self.bird_rect = self.bird.get_rect(midbottom = (70,50))
         self.playersize = (70,50)
         self.bird = pygame.transform.scale(self.bird, self.playersize)
 
         self.image = self.bird
         self.rect = self.image.get_rect(center = (40,300))
         self.gravity = 0
    
     def apply_gravity(self):
         self.gravity += 1
         self.rect.y += self.gravity
         if self.bird_rect.bottom == 404:
            self.running = False

     def player_input(self):
         keys = pygame.key.get_pressed()
         if keys[pygame.K_SPACE]:
             self.gravity = -12

     def update(self):
         self.player_input()
         self.apply_gravity()

 pygame.init()

 screen = pygame.display.set_mode((900,504))
 pygame.display.set_caption('Flappy Bird')

 running = False 

 score = 0
 clock = pygame.time.Clock() 

 game_over = ('Game Over')
 font = pygame.font.Font('Pixeltype.ttf', 50)

 background = pygame.image.load('background.png').convert()
 floor = pygame.image.load('floor.png').convert()
 floor_new = (900,504)
 floor = pygame.transform.scale(floor, floor_new)

 Player = pygame.sprite.GroupSingle()
 Player.add(player())

 obs_group = pygame.sprite.Group()

 while True:
     for event in pygame.event.get():
         if event.type == pygame.QUIT:
             pygame.quit()
             exit()
        
         else:
             if event.type == pygame.KEYDOWN and event.key ==  pygame.K_SPACE:
                 running = True 
    
     if running:
        screen.blit(background, (0,0))
        screen.blit(floor, (0,404))

        Player.draw(screen)
        Player.update()

        obs_group.draw(screen)
        obs_group.update()


     else:
         screen.fill('Red')
         screen.blit(screen, (0,0))


         scoremessage = font.render('Try Again', False, 'white')
         scoremessagerect = scoremessage.get_rect(center = (450,252))
         if score == 0:
             screen.blit(scoremessage, scoremessagerect)
     
     pygame.display.update()
     clock.tick(60)```