AirshipsThis galaxy is made nearly entirely of a group of Airships. On the first Airship, Mario will find several Octoombas aboard the ship. Past the enemies, there is a hole that holds a Cannon inside. Using the Cannon inside this hole, Mario can then fly to the second Airship. Here, Mario must avoid some Mobile Sentry Beams and a Magikoopa. At the front end of this ship is another hole that holds a Cannon inside. Using this Cannon, Mario can fly to the third Airship, however, there are some Bullet Bills he must avoid while doing so. It is possible to skip the second Airship and come to the third Airship by using the Cannon on the first Airship, flying to the third Airship, and grabbing the Pull Star nearby. On the third Airship, there are some Wigglers, a Mandibug and Lumalee hosting the Luma Shop. Here, Mario can Spin a Lever Switch to cause a wooden platform to move. On this platform, Mario must avoid some Cannonballs being fired at him from inaccessible Airships. After dodging/defeating some Scuttle Bugs that block the way, which are after the Cannonball area, Mario can depart from the wooden platform and climb aboard the fourth and final Airship. Here, Mario must battle Bowser Jr. on his flagship. When Bowser Jr. is defeated, Mario can receive a Grand Star, unlocking the Bedroom in the Comet Observatory.
This planet can be accessed if Mario aims to the right in the first Cannon. After doing so, the player can see a small green planet with several Goombas on it. This planet is very bouncy, allowing Mario to squish the Goombas here with ease. If all Goombas are defeated, Mario will be awarded with a 1-Up Mushroom. A Sling Star will then take Mario to the second Airship.
Sinking the AirshipsMario begins on the first Airship. Several Octoombas are here. A hole with a Cannon inside is also at the end of this ship. Avoiding the Octoombas, Mario can make his way into the hole to be sent into the aiming screen. Here, Mario can fire to the rightmost Flagpole to land on the second Airship, aim to the right and fire to the Trampoline Planet, defeat the Goombas and take the Sling Star to the second Airship, or he can aim to the third Airship and use a Pull Star to skip this Airship. If Mario lands on the second Airship, he must avoid some Mobile Sentry Beams and a Magikoopa and use another Cannon to fire to the third Airship. On this planet, Mario must avoid some Wigglers and a Mandibug. Lumalee is hosting her Luma Shop here, which Mario can use to buy a Life Mushroom or 1-Up Mushroom for thirty Star Bits. Anyway, Mario must Spin a Lever Switch to cause a wooden platform to start moving. He must board this platform and dodge the Cannonballs being shot at him from inaccessible Airships on both of his sides. After dodging the Cannonballs, Mario must eventually dodge/Spin some Scuttle Bugs blocking the way and then climb aboard the fourth Airship. Here, Bowser Jr. taunts Mario before beginning the battle. Here, Mario must throw Green Shells from a live Koopa Troopa at Bowser Jr.'s flagship while avoiding the Bullet Bills that the boss spawns from the cannons on his flagship. After the shell is thrown at the ship, another Koopa Troopa will spawn, which Mario can scare into its shell by jumping on it before picking it up and throwing it at the ship again. With each hit, Bowser Jr. will cause more mayhem to arise. He will spawn more Bullet Bills as well as summon Magikoopas. When Bowser Jr.'s flagship has been hit three times from a Koopa Troopa's shell, Mario will be awarded with a Grand Star, which unlocks the Bedroom in the Comet Observatory when collected.
- Koopa Troopas
- Bullet Bills
- Scuttle Bugs
- Sentry Beams
- Bowser Jr. (Boss)
- Trampoline Planet (optional)
- If Bowser Jr. is hit with a Star Bit fired at him via the Star Cursor, he will fall over and release twenty Star Bits. This only happens once. This can also be done using a Green Shell, however it does not count as a hit towards Bowser Jr.
- If Mario jumps on five Cannonballs shot from Bowser Jr.'s flagship in a row without touching the ground, he will receive a 1-Up.
- Bowser Jr.'s Fearsome Fleet in Super Mario Galaxy 2 is very similar to this galaxy. Coincidentally, they even have the same name in Italian (Flotta Navale di Bowser Jr.; stands for Bowser Jr.'s Naval Fleet)! This is possibly because these two galaxies require the use of items to defeat Bowser Jr. and that they both feature a Sling Star that can be used during the battle. No other boss galaxy in both Super Mario Galaxy and Super Mario Galaxy 2 features the use of a Sling Star during the battle.
- The music that is used as the main theme of this galaxy is also heard when Bowser attacks Princess Peach's Castle at the beginning of both Super Mario Galaxy and Super Mario Galaxy 2.
- The music features the same exact tune as the "Airship Theme" in Super Mario Bros. 3, though it is played slightly different for Super Mario Galaxy and Super Mario Galaxy 2.