Melty Molten Galaxy is a galaxy found in Super Mario Galaxy. This galaxy is the final "main" galaxy in the game, and the final galaxy to be orbited by a Daredevil and Purple Comet. As its name implies, it mostly focuses on fire and lava. Mario must have at least 52 Power Stars before he can access this galaxy.
Giant Lava Planet: This is a giant planet whose body contains mainly lava. It has some cooled areas here.
Starting Area: Mario starts on a big disk-shaped "continent" that contains a volcano. There is some lava on this continent.
Crashed Saucers: As he nears the section where the Hardening Lava planets are, Mario will pass by some crashed saucers. These do not have their own gravity.
Cooled Lava Zone: In the second mission, Mario will land here after he leaves the Stone Octagon Planet. It is a small network of islands that have been formed from hardening lava.
Steel Platform Area: In the third mission, just before he and the Fiery Dino Piranha square off, Mario will visit this area, which is riddled with steel platforms and Sling Stars. Lumalee sets up one of her shops here, and if she and Mario talk, she can provide either a 1-Up Mushroom or a Life Mushroom depending on what he wants.
Fiery Pull Star Path: In the first mission, Mario will land here after he ditches the volcano. To make his way through this section, Mario has to use the Pull Stars that riddle the area to his advantage. However, getting hit by the fireballs will cause Mario to fall onto the miniature lava planets, causing him to die.
Hardening Lava Planets: These two planets contain lots of lava. They are inhabited by Li'l Cinders. These planets still have their own gravity, even though their bodies have been nearly consumed by the main planet, reducing the planets to basically lava nodules. One of them spins and is visited only in the third mission. The other does not and is visited in the first and third missions.
Stone Octagon Planet: This planet is basically a large stone octagon whose core contains a Black Hole. It has three giant Thwomps that pound the surface constantly.
U-Tower Planet: This planet is shaped like the vowel U. It has some lava pools on its surface. The planet's "north pole" contains a Bullet Bill Blaster while its "south pole" has a Launch Star which Mario must free up with the Bullet Bills that are launched from the planet's north pole's Bullet Bill Blaster.
Star Ball Challenge Planet: During the second mission, Mario must roll a ball to the goal. There are holes in the planet that Mario can fall through if he is not careful.
Disk Planet: On his way to the planet that Fiery Dino Piranha lairs on, Mario will land here. There are five star chips that have been scattered throughout the planet's surface. The planet's gravity is normal, but the area is 2-D.
Fiery Dino Geo Planet: After he was defeated when he and Mario squared off, Dino Piranha retreated here. The fire infused his body, turning him into Fiery Dino Piranha.
Lava Sea Planet: On his way through the first mission, Mario can meet a Hungry Luma. This Luma tells him to deposit 80 Star Bits to create this planet, which has a rising and falling lava tide. There are five silver stars found here.
Mission 1 - The Sinking Lava Spire: Mario must climb the lava spire to get a star. He should be quick: it is sinking beneath his feet!
Mission 2 - Through the Meteor Storm: Mario makes his way through the meteor storm and then complete a Star Ball challenge.
Mission 3 - Fiery Dino Piranha: Dino Piranha is back! He uses fire to improve his powers! Mario must defeat him again!
Mission 4 (Secret) - Burning Tide: Mario must get at least 80 Star Bits and feed them to a Hungry Luma. This done, Mario must find five silver stars on the resulting planet.
If the player falls into the volcano, they can ground-pound on a switch to make Star Bits appear. But in the Purple Coin Mission of this galaxy, the switch is missing, most likely because 5 Purple Coins exist in there.
This galaxy has the highest amount of Star Bits needed to access the hidden star: 80. Interestingly, this is the only galaxy that needs 80 Star Bits to access the hidden star.
For some unknown reason, if the player uses the first Pull Star in the first mission, the player can't get the gravity to pull Mario back to the three ball-shaped planets: the gravity instead pulls him to a lava planet.
The Melty Monster Galaxy from Super Mario Galaxy 2 seems to be based off this galaxy, because both of them involve lava.