According to the documentation, "When the queue overflows an exception is thrown." however once the queue fills up and a new event should be added, it just silently fails to add it.
Simple test case:
import pygame pygame.init() scr = pygame.display.set_mode((300,300)) quit = False while not quit: for event in pygame.event.get(pygame.QUIT): print 'This should quit.' quit = True pygame.display.flip()
Starting the program, then hitting the close button will close the program normally. Starting the program, then filling the queue by clicking on the window a lot makes hitting the close button do nothing at all.