Super Mario Galaxy/Gusty Garden Galaxy

Gusty Garden Galaxy is accessible from the Bedroom observation dome. You need 24 Stars to enter.

Star 2: The Dirty Tricks of Major Burrows
Boss fight.

When you reach the boss, if you break the empty crystals using a Spin Attack in the first stage, before the boss starts chasing you, they will be out of your way later.

Star 3: Gusty Garden's Gravity Scramble
There is a hidden Star on this level. For the time being, ignore the ? Coins.

Star 4 (Daredevil Comet): Major Burrows's Daredevil Run
This Star is available when a Prankster Comet is in this Galaxy.

This is a repeat of the boss fight from Star 3, except you only have one life point.

Star 5 (Purple Comet): Purple Coins on the Puzzle Cube
This Star is available when a Purple Comet is in this Galaxy.

You need to collect 100 out of the total 150 Purple Coins, within a 2 minutes 30 seconds time limit.

Star 6 (Hidden): The Golden Chomp
Enter Star 3. Hit all the ? Coins, then use Rainbow Mario to destroy the golden Chomp Head.