Grand Finale Galaxy

The Grand Finale Galaxy is the final galaxy in Super Mario Galaxy. The galaxy is where Mario's home planet of Mushroom World resides. The galaxy is unlocked after all 120 Power Stars have been obtained with both Mario and Luigi, and is reached by talking to the fourth Green Luma on the Trial Planet. This galaxy has the 121st Power Star for both Mario brothers. The level takes place in Toad Town (also known as the Castle Gardens) from the beginning of the game; with creatures from later parts of the game now attending the Star Festival, including Penguins, Bees, Gearmos, and Star Bunnies, the four major NPC types in the game. The Toad Brigade and their ship, the Starshroom, are found outside of the castle.

After collecting all the Purple Coins, the Mailtoad will receive a message. If the player talks to him, he will send a congratulatory picture to the Wii message board. This picture differs depending on whether the player spoke to the Mailtoad with Mario or Luigi. With Mario, him and Peach will be standing in the starting planet of Good Egg Galaxy with some Lumas, including Mario's Luma. With Luigi, him and Rosalina will be standing by the castle with the Toad Brigade. The picture can also be sent to friends.

Interestingly enough, on the list of galaxies, this galaxy is simply called "Grand Finale", lacking the "galaxy" name at the end that all other galaxies on the list have.

The Mushroom World (Starting Planet)
This is the main planet of the Galaxy and where most Mario games take place, although Super Mario Galaxy only shows Toad Town and the exterior of Princess Peach's Castle. The castle and the area around it is based on the design introduced in Super Mario 64, containing a large lake with a river flowing into it, but expanded to include a pathway to Toad Town. The path goes through the town and into the castle.

There is an invisible wall, like the ones found at the limits of the levels in Super Mario 64, that stops the player from entering the castle itself.

The Star Festival
The Star Festival is the only level of the Grand Finale Galaxy in Super Mario Galaxy, and is named after the event at the beginning of the game, which occurs every 100 years.

The mission requires the player to collect all 100 Purple Coins in order to receive the 121st Power Star. Before collecting the star, the player may talk to the Mailtoad to receive a congratulatory message and attached picture, which is sent to the Wii Message Board.

Trivia

 * Contrary to popular belief, it is possible to take damage in this level. It can be done by jumping into the fire roasting food just past the gate to Peach's castle area.