Flash Black Galaxy

Flash Black Galaxy is a galaxy appearing in the game Super Mario Galaxy 2. It is located in World 6. The galaxy takes place in a haunted mansion. However, everything is pitch black except for the occasional second of lightning, which shows the area. Many gaps are in the ground. Yoshi is found here and the level makes extensive use of the Blimp Fruit. Common enemies and obstacles here include Mines, Pumpkinhead Goombas, and Flaptacks.

Starting Planet
The starting planet is a dark, huge and mazy tower. To get to its top, Mario must use Blimp Yoshi and avoid the Mines and the other enemies. The Launch Star is located at the top right of the tower. The Comet Medal is found on this planet as well. Enemies here include Jack O'Goombas and Paragoombas.

Maze Planet
This planet is a dark maze with Octoboos lurking on it. Mario must walk carefully to avoid falling in space. There are five Silver Stars in this planet, and several Flaptacks too. This planet is similar to the last planet in Matter Splatter Galaxy in the first Super Mario Galaxy.

Jumping Around in the Dark
To complete this mission, Mario must make his way to the Maze Planet. To do so, he must get Yoshi in the first planet and feed him a Blimp Fruit. He'll be able to float in the air and get past the vertical maze. The Launch Star can be found in the right side of the maze. After Mario uses it, he'll get to the maze planet. Here, he must collect all of the Silver Stars without falling. Once all of them are collected, a Power Star will appear at the end of the planet. Mario must get to its location and grab it.

Dark Octo-Army Romp
After the Prankster Comet has been unlocked, Mario ends up on the Maze Planet. This time, he has to defeat all of the thirty Octoombas within eighty seconds. There is a Yoshi Egg at the end of the level that may help the plumber defeat the enemies easily. If he defeats all enemies, he earns a Power Star.

Green Star 1
This Green Star is located on the first planet, at the highest right spot. Mario has to use Blimp Yoshi to get up there and grab it.

Green Star 2
This star is located on the Maze Planet. Mario has to make his way to the end of the planet to notice the Green Star floating below. He has to fall carefully to catch it.

Trivia

 * The galaxy's name "Flash Black" is pun on "flashback" and "black", since most of the time the galaxy is black to the point where it is invisible to the eye until it flashes like a camera.