This glitch allows you to access the rooftop at Flash Black Galaxy.
-Go to the second planet, and keep Yoshi.
-Go to a platform and look left at the building. If you're lined up with the building, begin to infinite flutter to the rooftop. (To infinite flutter, jump and hold A. Just after you start fluttering, tap Z and let go quickly, then immediately let go of A and repeat until you reach the top. Don't take too long to press Z.)

Notes: If you land at the back half of the roof, you can move in 3D and use the first person camera. If you either land or run to the front half, it will limit you to 2D, like inside. Running off the edges will cause you to fall. You can access the beginning of the course again by using this glitch.

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