Trial Galaxies

The Trial Galaxies are secret levels found in Super Mario Galaxy. If the player recovers three special Green Power Stars, three Green Lumas will appear and activate a Green Launch Star. By using it, Mario can access a Planet orbiting the Comet Observatory. There, three additional Green Lumas can each transform into Launch Stars that will take Mario to the three Trial Galaxies.

The Trial Galaxies are three galaxies known as the Rolling Gizmo Galaxy, the Bubble Blast Galaxy, and the Loopdeswoop Galaxy. Once all 120 stars are collected with Luigi as well as Mario, a fourth Green Luma will appear and access to the Grand Finale Galaxy is granted.