save project

my_game.py

@@ -60,7 +60,7 @@ while True:
         if index >= 5:
             index = 0
     # 将背景图画上去
-    bg -=8
+    bg -=4
     screen.blit(background, (bg, 0))     # 远处背景
     if bg <= -1000:
         bg = 0