diff --git a/game_functions.py b/game_functions.py
new file mode 100644
index 0000000..d35f2d4
--- /dev/null
+++ b/game_functions.py
@@ -0,0 +1,236 @@
+import sys
+from time import sleep
+
+import pygame
+
+from bullet import Bullet
+from bazi import Bazi
+
+def check_keydown_events(event, ai_settings, screen, man, bullets):
+    """对按键做出反应"""
+    if event.key == pygame.K_RIGHT:
+        man.moving_right = True
+    elif event.key == pygame.K_LEFT:
+        man.moving_left = True
+    elif event.key == pygame.K_SPACE:
+        fire_bullet(ai_settings, screen, man, bullets)
+    elif event.key == pygame.K_q:
+        sys.exit()
+        
+def check_keyup_events(event, man):
+    """响应按键的发布"""
+    if event.key == pygame.K_RIGHT:
+        man.moving_right = False
+    elif event.key == pygame.K_LEFT:
+        man.moving_left = False
+
+def check_events(ai_settings, screen, stats, sb, play_button, man, bazis,
+        bullets):
+    """响应按键和鼠标事件"""
+    for event in pygame.event.get():
+        if event.type == pygame.QUIT:
+            sys.exit()
+        elif event.type == pygame.KEYDOWN:
+            check_keydown_events(event, ai_settings, screen, man, bullets)
+        elif event.type == pygame.KEYUP:
+            check_keyup_events(event, man)
+        elif event.type == pygame.MOUSEBUTTONDOWN:
+            mouse_x, mouse_y = pygame.mouse.get_pos()
+            check_play_button(ai_settings, screen, stats, sb, play_button,
+                man, bazis, bullets, mouse_x, mouse_y)
+            
+def check_play_button(ai_settings, screen, stats, sb, play_button, man,
+        bazis, bullets, mouse_x, mouse_y):
+    """当玩家点击Play时开始一个新游戏"""
+    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
+    if button_clicked and not stats.game_active:
+        # 重置游戏设置
+        ai_settings.initialize_dynamic_settings()
+        
+        # 隐藏鼠标光标
+        pygame.mouse.set_visible(False)
+        
+        # 重置游戏统计信息
+        stats.reset_stats()
+        stats.game_active = True
+        
+        # 重置记分板图像
+        sb.prep_score()
+        sb.prep_high_score()
+        sb.prep_level()
+        sb.prep_mans()
+        
+        # 清空靶子和子弹的名单
+        bazis.empty()
+        bullets.empty()
+        
+        # 创建一个人并将其置于中心
+        create_fleet(ai_settings, screen, man, bazis)
+        man.center_man()
+
+def fire_bullet(ai_settings, screen, man, bullets):
+    """发射一颗子弹，如果还没有达到极限"""
+    # 创建新项目符号，添加到项目符号组
+    if len(bullets) < ai_settings.bullets_allowed:
+        new_bullet = Bullet(ai_settings, screen, man)
+        bullets.add(new_bullet)
+
+def update_screen(ai_settings, screen, stats, sb, man, bazis, bullets,
+        play_button):
+    """更新屏幕上的图像，然后切换到新屏幕。"""
+    # 重新绘制屏幕，每次通过循环
+    screen.fill(ai_settings.bg_color)
+    
+    # 重画所有子弹，在人和靶子后面
+    for bullet in bullets.sprites():
+        bullet.draw_bullet()
+    man.blitme()
+    bazis.draw(screen)
+    
+    # 绘制分数信息
+    sb.show_score()
+    
+    # 如果游戏处于非活动状态，则绘制播放按钮
+    if not stats.game_active:
+        play_button.draw_button()
+
+    # 使最近绘制的屏幕可见
+    pygame.display.flip()
+    
+def update_bullets(ai_settings, screen, stats, sb, man, bazis, bullets):
+    """更新子弹的位置，清除旧子弹"""
+    # 更新子弹位置
+    bullets.update()
+
+    # 扔掉已经消失的子弹
+    for bullet in bullets.copy():
+        if bullet.rect.bottom <= 0:
+            bullets.remove(bullet)
+            
+    check_bullet_bazi_collisions(ai_settings, screen, stats, sb, man,
+        bazis, bullets)
+        
+def check_high_score(stats, sb):
+    """查看是否有新的高分"""
+    if stats.score > stats.high_score:
+        stats.high_score = stats.score
+        sb.prep_high_score()
+            
+def check_bullet_bazi_collisions(ai_settings, screen, stats, sb, man,
+        bazis, bullets):
+    """对子弹和靶子的碰撞做出反应（碰撞检测）"""
+    # 移除所有碰撞的子弹和靶子
+    collisions = pygame.sprite.groupcollide(bullets, bazis, True, True)
+    
+    if collisions:
+        for bazis in collisions.values():
+            stats.score += ai_settings.bazi_points * len(bazis)
+            sb.prep_score()
+        check_high_score(stats, sb)
+    
+    if len(bazis) == 0:
+        # 如果靶子都被摧毁，开始一个新的关卡
+        bullets.empty()
+        ai_settings.increase_speed()
+        
+        # 提高水平
+        stats.level += 1
+        sb.prep_level()
+        
+        create_fleet(ai_settings, screen, man, bazis)
+    
+def check_fleet_edges(ai_settings, bazis):
+    """如果有靶子到达边缘，请做出适当的反应"""
+    for bazi in bazis.sprites():
+        if bazi.check_edges():
+            change_fleet_direction(ai_settings, bazis)
+            break
+        
+def change_fleet_direction(ai_settings, bazis):
+    """放下整个队列，改变队列的方向"""
+    for bazi in bazis.sprites():
+        bazi.rect.y += ai_settings.fleet_drop_speed
+    ai_settings.fleet_direction *= -1
+    
+def man_hit(ai_settings, screen, stats, sb, man, bazis, bullets):
+    """回应被靶子碰撞的人"""
+    if stats.mans_left > 0:
+        # 向左递减
+        stats.mans_left -= 1
+        
+        # 更新分数面板
+        sb.prep_mans()
+        
+    else:
+        stats.game_active = False
+        pygame.mouse.set_visible(True)
+    
+    # 清空靶子和子弹的名单
+    bazis.empty()
+    bullets.empty()
+    
+    # 创建一个新角色，并将人居中
+    create_fleet(ai_settings, screen, man, bazis)
+    man.center_man()
+
+    sleep(0.5)
+    
+def check_bazis_bottom(ai_settings, screen, stats, sb, man, bazis,
+        bullets):
+    """检查是否有靶子到达屏幕底部"""
+    screen_rect = screen.get_rect()
+    for bazi in bazis.sprites():
+        if bazi.rect.bottom >= screen_rect.bottom:
+            # 人被击中一样
+            man_hit(ai_settings, screen, stats, sb, man, bazis, bullets)
+            break
+            
+def update_bazis(ai_settings, screen, stats, sb, man, bazis, bullets):
+    """
+    检查靶子是否处于边缘，然后更新靶子中所有靶子的位置
+    """
+    check_fleet_edges(ai_settings, bazis)
+    bazis.update()
+    
+    # 寻找人和靶子碰撞
+    if pygame.sprite.spritecollideany(man, bazis):
+        man_hit(ai_settings, screen, stats, sb, man, bazis, bullets)
+
+    # 在屏幕底部寻找靶子
+    check_bazis_bottom(ai_settings, screen, stats, sb, man, bazis, bullets)
+            
+def get_number_bazis_x(ai_settings, bazi_width):
+    """确定排成一行的外星人的数量"""
+    available_space_x = ai_settings.screen_width - 1 * bazi_width
+    number_bazi_x = int(available_space_x / (2 * bazi_width))
+    return number_bazi_x
+    
+def get_number_rows(ai_settings, man_height, bazi_height):
+    """确定适合屏幕的外星人行数"""
+    available_space_y = (ai_settings.screen_height -
+                            (1 * bazi_height) - man_height)
+    number_rows = int(available_space_y / (2 * bazi_height))
+    return number_rows
+    
+def create_bazi(ai_settings, screen, bazis, bazi_number, row_number):
+    """创建一个靶子，并将其放置在行中"""
+    bazi = Bazi(ai_settings, screen)
+    bazi_width = bazi.rect.width
+    bazi.x = bazi_width + 2 * bazi_width * bazi_number
+    bazi.rect.x = bazi.x
+    bazi.rect.y = bazi.rect.height + 2 * bazi.rect.height * row_number
+    bazis.add(bazi)
+
+def create_fleet(ai_settings, screen, man, bazis):
+    """创造一个完整的靶子队列"""
+    # 创建一个靶子，并查找一行中的靶子数量
+    bazi = Bazi(ai_settings, screen)
+    number_bazis_x = get_number_bazis_x(ai_settings, bazi.rect.width)
+    number_rows = get_number_rows(ai_settings, man.rect.height,
+        bazi.rect.height)
+    
+    # 创造外星人舰队
+    for row_number in range(number_rows):
+        for bazi_number in range(number_bazis_x):
+            create_bazi(ai_settings, screen, bazis, bazi_number,
+                row_number)