Trial Galaxies

The Trial Galaxies are a group of three particularly difficult levels found in Super Mario Galaxy. They are comprised of the Rolling Gizmo Galaxy, the Bubble Blast Galaxy, and the Loopdeeswoop Galaxy.

If the player recovers three special Green Power Stars, three Green Lumas will appear on the Comet Observatory, which will then activate a green Launch Star located near the Garage. By using it, Mario is able to access the Planet of Trials, a small planet orbiting the Comet Observatory. There, three more Green Lumas will each transform into an additional green Launch Star when talked to. These Launch Stars will take Mario to the three Trial Galaxies. Once the player has collected all 120 Power Stars in the game with both Mario and Luigi, a fourth Green Luma will appear on the reverse side of the Planet of Trials. This Green Luma will allow the player to go to the Grand Finale Galaxy (the Mushroom World) when Mario talks to it.

Trivia

 * If Mario tries to fly to the Trial Planet, he will fall back down to the observatory.