Gateway Galaxy
The Gateway Galaxy is one of the many Galaxies from Super Mario Galaxy for the Wii. Princess Rosalina calls this galaxy the "Gateway to the Starry Sky". It serves as the opening level for the game and is the location of the Cosmic Observatory. This is the first Galaxy in the game, and after Mario clears the first level in the Galaxy, he won't be able to return until he unlocks the Garden, later on in the game.
Levels
Grand Star Rescue
When Mario awakens on this planet, a Space Bunny will challenge him to a game of hide-and-seek. Follow the bunny until he reaches his two friends, who will run and hide. One is found near a crate, another in a crater, and the last in a Warp Pipe. Catch them all, and a new structure on the planet will appear. Mario will meet with Princess Rosalina and gain the Star Spin ability. Spin the nearby Launch Star to reach the next planet, which has five Star Chips scattered about. Grab the Star Chips to make a Launch Star and blast Mario to the next planet. Here, a Luma in a cage tells Mario that one of the Goombas on the planet has the key. Kill the Giant Goomba near the top of the planet to free the Luma and enter the Warp Pipe. The inside of the planet is filled with yellow switches and moving electrical walls. Mario needs to stand on all the yellow switches to turn them blue, which will reveal the Grand Star.