Super Mario Galaxy/Buoy Base Galaxy

Buoy Base Galaxy is accessible from the Kitchen observation dome. You need 30 Stars to enter.

This Galaxy's main feature is a floating tower half-submerged in water.

Star 1: The Floating Fortress
(Note: I edited it, and this is my best description ever! Don't edit it!)

This galaxy has a huge tower with a planet above it. But how can you get up there?

So....you're going to have to go underwater. There are lots of Bloopers to avoid, but do you see a cage under the tower? That's the underwater weight! It means you have to use Bullet Bills to break it, so get on front of a Bullet Bill launcher and it will shoot. When it sees you, it will follow you, so get behind the cage. When the Bullet Bill hits the cage, it will explode and the tower will get up to the surface of the water.

It's now your chance to get up there, but the Bubble Shooters are left on. If you get in a bubble, it will push you off the tower, so be careful. There's also a stone that can push you off the tower by moving forward. So wait for that stone to go back, and quickly wall-jump.

Now there is a kaliente that shoots boulders, so quickly jump on it or spin into it so it won't bother you when you're going up. There are three Thwomps ahead, so be careful, Thwomps are huge and can crush you by falling on you. But when it is on the ground, it goes up, so wait for it to go up, and go past one.

When you pass all three Thwomps, you'll remember about the Bubble shooters, and you can see a valve. Just spin on top of it and a green Topman appears and the Bubble shooters will go off. The green Topman is the newest topman ever discovered. Spin into it or jump on it and then it is used as a spring. Do that on the right wall with a bolt on it. Spin into it and all platforms near the top of the tower will start moving.

Now your goal is to collect all Blue Star Chips. Go on the bottom of the moving platforms, but watch out for lightning balls, because the platforms has holes so it can let the lightning ball go through. Just stay on the bottom and go through the lightning balls until you see a blue star chip. Go on higher platforms and you'll see a star chip on one of the Thwomps, so be careful. When it is on the ground, land on the Thwomp and it will go up, and you'll get the star chip. Now run through the Thwomps again and reach the part with the green Topman, and use it as a spring to get back on the platforms. Jump on higher platforms until you see a goomba and a blue star chip. Spin the goomba in water so it won't bother you and get the star chip. Now you can see a long moving platform. Get on it, and it will send you to a platform with a star chip. Then go to the very top of the tower: just as you expected, a green topman, but only the head. When it sees you, it sends out four yellow topman. Jump on the green topman head to get the final blue star chip.

When the pull stars appear, you have permission to get on the planet on top of the tower. There are two boltheads that make lightning waves. Wait for the first one to stop making lightning waves for a few seconds, and jump over the lightning waves on the bolthead on top, then spin on top of it to make the planet underwater, and there is a power star underwater.

Star 2 (Hidden Green): The Secret of Buoy Base
This is a green power star. Remember the Bullet Bill Launchers? Get on front of the one near the caged pipe, and it will shoot. When it sees you, it follows you. Get behind the caged pipe so the Bullet Bill will break it. Get inside the pipe.

Now there are lots of Bullet Bill Launchers. Dodge them on your way, and then you'll see the green power star, caged up, with lightning balls guarding it. Get near a Bullet Bill launcher and make it chase you. Be careful not to make the Bullet Bill hit the lightning balls, or it'll explode. If it gets past a lightning ball, break the cage.

Did you find?

 * 1-Up Mushroom on a platform near the top of the tower.