The Grandmaster Galaxy is the final galaxy of Super Mario Galaxy 2, located in World S. It is analogous to the Grand Finale Galaxy from Super Mario Galaxy because the player must collect all 240 Power Stars to unlock it. It contains two Power Stars: one for completing the level and another one for a second completion under Daredevil Comet conditions. In the latter case, the player gets the Star from Rosalina. This is the only Galaxy where Green Stars do not appear because the player has to collect all of the Green Stars in the game in order to unlock this galaxy.
NOTE: Unless otherwise noted, all names are unofficial.
In the first area, Mario has to use Yoshi to swing on the flower grapples to reach the Launch Star at the end of the area. There are several obstacles along the way, such as Mines and Bullet Bills. Paragoombas appear in The Ultimate Test and are replaced by Choppahs in The Perfect Run. A Toad can also be found on this planet and will shout Yoshi's name when spoken to.
After using the Launch Star from the first planet, Mario lands on a planet with Flipswitch Panels. It has a backdrop showing moving sprites of items from Super Mario Bros.. Mario has to activate all 21 Flipswitch Panels while avoiding Sentry Beams to reveal the Launch Star.
Electric Maze Area
After landing, Mario finds a Cloud Flower and a fan producing an upward gust. Mario has to use the Cloud Flower to maneuver to the Launch Star at the end of the area, with more Cloud Flowers subsequently being supplied along the way. There is also a 1-Up Mushroom at the top left which can be reached using the Cloud Flower.
This area contains planets made of Shrinking Tiles and Red-Blue Panels. Octopuses and Sentry Beams are also found in the area. Mario has to avoid all the obstacles in order to successfully reach the Launch Star to the next area at the end of the section.
Pull Star Area
In the beginning of the area, there are some electrified blocks followed by a long segment of Pull Stars, which Mario must use to reach the Launch Star while avoiding electrical currents, mines, and Paragoombas.
Hammer Bro Planets
The ending platform has three Boomerang Bros., which Mario must defeat to reveal a Power Star (or a Launch Star in the Daredevil run). Note that defeating the Hammer Bros is not necessary for getting the Power/Launch Star to appear.
The Comet Medal for this galaxy is located on the far right side of these planets, next to some platforms with some torches (as shown on the screenshot). In The Perfect Run, the Comet Medal is replaced with a 1-Up Mushroom.
This area is only accessible during The Perfect Run. It is a small planet with a small house and strongly resembles the Gate in Super Mario Galaxy. Rosalina and the final Power Star are found on this planet. There is also a 1-Up Mushroom behind the house. If Mario falls off the planet, he will still lose a life and have to go back to the start.
The Ultimate Test
This mission is unlocked once the player gets a total of 240 Stars. The player must complete all the various tasks mentioned above. There are checkpoint flags at the beginning of the Electric Maze Area, the Platform Planets, and the Pull Star Area. Throughout the mission, the player can also speak to the Toad Brigade members. This mission, along with the Daredevil Run, is the only time that the Toad Brigade leader is seen sleeping. Yellow Toad is also asleep, and if the player speaks to him, he mumbles about Star Bits, giving the player a hint on how to unlock the final mission.
The Perfect Run
The player must redo the The Ultimate Test mission, but under Daredevil Comet conditions. There aren't any Checkpoint Flags in this mission and, in the first area, the Paragoombas have been replaced with Choppahs and more mines have been added. Additionally, after defeating the Boomerang Bros. at the end of the level, rather than the Power Star appearing, a Launch Star appears that takes the player to the Gate-like planet where the Power Star and Rosalina are located.
Names in other languages