This page offers a guide on how to find the Hidden Green Power Star in The Floating Fortress level in Buoy Base Galaxy. This is the first Green Star available to the player. There are three Green Stars in the game and they are required to unlock the Trial Galaxies.
Reveal the Warp Pipe
Firstly, you’ll need to find the caged warp pipe under the water during The Floating Fortress level. Nearby to the caged warp pipe is a Torpedo Ted spawner. Guide the Torpedo Ted into the cage to reveal the warp pipe.
Guide the Bullet Bills
In this next area, multiple Bullet Bills will spawn along a path. Your task is to guide at least one of the Bullet Bills along the path then up to the caged Green Power Star. This is easier said than done as there are Big Amps circling the cage that will explode the Bullet Bills if they hit them. If you need to, take the Bullet Bills around the platform a little and wait for an opening instead of heading straight from the path to the caged Green Star.
Green Power Stars
Upon grabbing the Green Star, Rosalina will tell you about the Green Luma who is the Guardian of the Trial Galaxies. He needs you to collect two more of these elusive green stars so he can power the Star Launcher to the Planet of Trials.