Melty Molten Galaxy

The Melty Molten Galaxy is a galaxy in Super Mario Galaxy. It's quite a large galaxy, made completely of lava and rock. There's many Star Rings here, allowing mario to traverse the massive planet.

Lava Planet
The Lava Planet is a Mega Planet in the upcoming game Super Mario Galaxy. It contains many obstacles and features relating to the Super Mario 64 level, Lethal Lava Land. Obviously, it is covered in a sea of lava. This level introduced trailer-viewers to a new enemy and new explorable uses for Spring Stars.

There is a small volcano on this planet with a Boost Star on top, there are outrageous obstacles over its atmosphere that can be explored with Float Stars, hot rock hills, decimatable rocks, stands in the lava such as the ones in Ricco Harbor in the game Super Mario Sunshine, and more.