Exploring the Cosmic Cavern

Exploring the Cosmic Cavern is the second level of the Cosmic Cove Galaxy in Super Mario Galaxy 2. Due to the activated switch in the first mission, the water in this mission is frozen. As the title of the level implies, players traverse through the level and its cave to free a trapped Luma and use its Launch Star transformation to launch themselves to another planet where the Power Star is contained in.

Layout
Upon entering the galaxy for the second time, players find a Luma trapped in a glass cage. To get the Key and free the Luma, players have to run across the frozen water until they reach a green Warp Pipe. They must use it to get into an underwater cavern. Here, they have to make their way to the bottom of the cavern and use another Warp Pipe to warp to the Water Maze. In this area, the player need to navigate through a maze-like area composed completely of water. Many mines patrol the area and can knock the player into a Black Hole. Near the end of this area is a key.

After getting the key, the player must go through the warp pipe at the end of the area which takes them back to the galaxy's entrance. The Luma then thanks players and transforms into a Launch Star. After landing on a Starshroom and taking its Launch Star, players end up on the last planet.

In the next planet, players have to use the Spin Drill on the right spot to get to the other side, while being aware about the Fizzlits. On this planet, they need to defeat all of Mechakoopas on this side of planet until one releases a key. This key disables a shield that was protecting a patch of dirt with water leaking out of it. When players use the Spin Drill on this hole, the planet gets covered with water, and players can now grab the Power Star.

Green Star 2
When players get to the Water Maze, they should look for a platform with a Goomba on it. The Green Star is to the right of the platform and needs careful precision and aim if players need to obtain it.

Green Star 3
Players should make their way back to the Water Maze. Player should swim to the top where the key is. After getting the key, players should go to the platform on the right and perform a Long Jump to the Green Star off to the left.