Yo i had an issue with seeing the game screen and i found the problem, you can change line 15
screen = pygame.display.set_mode((screen_width, screen_height))
to this
screen = pygame.display.set_mode((screen_width, screen_height),pygame.SCALED | pygame.FULLSCREEN)
What pygame.SCALED does is to make sure that the game resolution scales with the Monitor resolution and what pygame.FULLSCREEN does is that it fits the game to the monitor screen