Bowser's Galaxy Generator is the final level in the main story of Super Mario Galaxy 2. However, it is not the final level as there is a secret World S only accessible upon completing this level.
First appeared in the YouTube Poop, The Theif Who Tried to Steal Miami. This takes the credits.
Bowser's Fortified Fortress
Mario crosses the entire fortress, dodging lava pits, fire balls, Banzai Bills, crushing walls, and many different types enemies in hopes are confronting Bowser for the final time. Upon reaching Bowser, the fight is played the same as the previous ones, only after his defeat, there is a part two in which Mario mush fling meteorites at Bowser while flying through space at what seems to be a very fast pace.
Bowser's Big Bad Speed Run
The speed run will give you thirty seconds. You collect clocks to increase time by ten seconds. In the section of Banzai Bills, they are replaced with Octoombas.
If you succeed the level, the star is where the pole used to be in the original mission.
Green Star 1
The first green star must require the Flower. Try to control Mario to the Green Star, which is in the most dangerous and risky spot.
Green Star 2
Green Star 2 is located off the tilting platform. Defeat the magikoopa first. Then you must have two clouds. Long jump and spin twice, then get the star.