Super Mario Galaxy 2/Flip-Out Galaxy

Star 2 (Prankster Comet): Cosmic Clone Wall Jumpers
This star is exactly like the first star, but with the added difficulty of Cosmic Clones.

Green Star 1
From the start, wall jump up the first two flipping walls, spinning between each jump like at the end of the first two stars. Eventually you will land on top of the blue platform and see a 1-Up. Go up to it and grab it if you want. If you move up to the edge and look closely, You will notice the Green Star. Jump down to it. This may take several tries.

Green Star 2
This is the only Green Star to be hidden in a Prankster Comet mission. On the platform with the star, go to the middle of the part of the platform jutting out on the right. Jump down, and when you see the star, spin to perfect your fall.