The special stages in Advance 2 can be completed easily if you keep your speed up and collect large groups of rings at once. Use the D-Pad to steer your character through those long lines of rings as fast and long as you can. You'll hear a chime and an X with a number beside it appear above your character. With this started you're getting bonus rings for picking up large groups of rings. Use this method as much as possible and you'll be able to get up the needed amount quickly.