World S

World S: Here We Go!, also known as Special World, is the seventh and last world featured in Super Mario Galaxy 2. It is located high in the sky of an unknown planet with colorful star-shaped continents. It holds a total of seven galaxies, the last of which, the Grandmaster Galaxy, can only be accessed by collecting all 120 Power Stars as well as all 120 Green Stars.

Galaxies

 * Mario Squared Galaxy
 * Rolling Coaster Galaxy
 * Twisty Trials Galaxy
 * Stone Cyclone Galaxy
 * Boss Blitz Galaxy
 * Flip-Out Galaxy (Hungry Luma)
 * Grandmaster Galaxy

Trivia

 * Almost all the galaxies in this world are references to other Mario games.
 * The placements of the seven galaxies form an 'S', hinting at the name of the World.
 * This is the only World in the entire game where every galaxy has two regular missions, and all but one have two Green Star levels.
 * The music for this world is a slowed-down version of Gusty Garden Galaxy's music (the galaxy from Super Mario Galaxy).
 * One of the galaxies is a ball-riding galaxy, and the course is almost identical to Rainbow Road from the Mario Kart series.