# 按叉叉會結束程式
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
    
    if state == 'aim':
        keys = pygame.key.get_pressed()
        if keys[pygame.K_LEFT]:
            launcher.tilt_left()
            
        elif keys[pygame.K_RIGHT]:
            launcher.tilt_right()
        
        elif keys[pygame.K_SPACE]:
            launcher.launch_balls(ball_group)

            # 準備下一個state
            state = 'launch'
            frame_counter = 0
            ball_counter = 1



    elif state == 'launch':
        frame_counter += 1
        # 每四幀畫面發射一顆球
        if frame_counter % 4 == 0:
            # level 幾就有幾顆球
            if ball_counter < level:
                launcher.launch_balls(ball_group)