The Dreadnought Galaxy is a galaxy in Super Mario Galaxy. It is quite similar to the Battlerock Galaxy since it centers around the titular station, the Dreadnought (which is actually a battleship). This galaxy plays a remixed version of the Space Fantasy theme, with strings and brasses and less synth, another feature coming from the Battlerock Galaxy, although the original Space Fantasy returns in some areas as well.
Infiltrating the Dreadnought
In this mission, Mario first lands on the laser planet. Mario must go through a tricky obstacle course to find the Power Star.
Dreadnought's Colossal Cannons
Mario has to go through another obstacle course, but this course involves dodging many cannons
Revenge of the Topman Tribe
Mario must battle the Topmen again. The level culminates in a second battle against Topmaniac.
Topman Tribe Speed Run (Speedy Comet in orbit)
This mission is only accessible, unless already completed, if a Speedy Comet is in orbit.
Battlestation's Purple Coins (Purple Comet in orbit)
Dreadnought's Garbage Dump
This is a hidden star in the Topman level. Again, you have to blow up garbage, but this time the challenge is harder.
This planet is the lower of the Beam Planets in the galaxy. It appears in Infiltrating The Dreadnought, Revenge Of The Topman Tribe, Topman Tribe Speed Run, and Dreadnought's Garbage Dump. In the first one, it is one of the Beam Planets and spins counter clockwise while firing lasers at the other. In the latter three, it has its beams removed and Mario starts on the side unlike on the bottom like he did last time. It does not spin. In Mission 2: Dreadnought's Colossal Cannons, Mario oddly omits this planet from his itinerary. For more info about the Beam Planets, see below.
These planets earned their name due to a laser network connecting them. Their arrangement makes them similar to an hourglass. Mario starts his trek through the galaxy on the lower one in all but the Second Mission and the Purple Coin mission. In the first mission, the top planet spins clockwise, but in the other missions, it is replaced by the Sphere Planet.
This is the main feature of the galaxy. It is a giant 2-mile long spaceship (For the purpose of this measurement, we will count Mario as 2 metres tall.) It has cannons and spikes that can damage Mario, causing him to lose one Health Point. At the top of the Dreadnought, there is a pool of water. There are also Springs and Pull Stars littered all over.
The entrance has three Goombeetles and a Warp Pipe. The inside portion is a side-scrolling area with hazards such as Amps, Cannons, and moving walls. At the end is another Warp Pipe. The gravity of this area can be changed with Gravity Arrows, which are necessary to proceed through the area. In the purple coins mission, after collecting the last purple coin, they land here, while the Goombeetles and the entrance pipe (along with its case) were replaced by a Gearmo who awards the player a star if he/she collects all of the purple coins.
This area has various cylinders that fall when Mario makes his way to a higher level. On the top parts are a pair of moving walls and a Launch Star.
Colossal Cannons Area
This is a section on the side of the Dreadnought which consists of several platforms of different sizes that travel along a path. There are obstacles such as cannons and electric currents. At the end is a Power Star.
Artillery Walls Area
The Artillery Walls are two walls that face each other located in the Dreadnought. The cannons shoot Cannonballs, and there are Pull Stars in the middle. There are also Mines in the way that can be taken out with a Star Bit. Mario has to avoid the cannonballs while traveling by them. Mario starts his trek on a football-shaped planet in this area.
These two metal blocks earned their name from their cube-like appearance. One orbits the Aqua Planet (below) and has Eye Beamers. These enemies can electrocute their target by sweeping their laser around, so Mario has to make his way past them. The other orbits the Sphere Planet and has a Spring Topman which can propel Mario into the air, so as to allow him to grab the Blue Star Chips that from Pull Stars to reach the Launch Star that leads to the Artillery Wall section of the Dreadnought.
This planet is a small grass planet with some patches of metal. It is a medium-sized planet with a Bill Blaster and several Goombeetles. There is a vault that when broken, floods the planet, which is necessary to complete the level. There are also a lot of platforms with Eye Beamers whose lasers move across the water and a pair of Ocean Small Turtles that take Mario from platform to platform. Above it is a small cubical planetoid. Some metallic structures are above the water, and one of them has a Power Star.
Chibi Wanwan Planet
This planet serves as the Starting Planet for Mission 2: Dreadnought's Colossal Cannons. It has earned its name since it is the planet where Chibi Wanwans make their lair. The Chibi Wanwan Planet has three parts. In the first part is a Bolt Lift that moves forwards or backwards depending on how much weight is on it. Beneath it is a green platform with Bob-ombs. The second part has several Flipswitch Panels which Mario must press by avoiding the Chibi Wanwans that constantly fall from the dog shacks. If he presses them all, Mario can access the third part. In this part are two more screws and two Octopodes that must be defeated, causing a Launch Star to appear.
This is a planet shaped like half a sphere. It is inhabited by a Gearmo that cleans the garbage. There are also some Bob-ombs that Mario must use to blow up the garbage in order to obtain a Power Star from the Gearmo.
This planet did not appear in the first mission. In the other missions, it is replaced with one of the Beam Planets, though it is positioned higher above the Starting Planet than the Beam Planet it replaced. It has several cylinder structures sticking out. After making his way onto the planet's south pole from the Starting Planet, Mario must knock two Spiky Topmen into an electrical barrier to free a trapped Luma. After being freed from his prison, the Luma will transform into a Sling Star that will lead Mario to the Cube Planet.
This is a long, zigzagging landing platform with Montys, Treasure Chests and Ring Beamers that shoot electric waves at Mario. White circles around the Ring Beamers indicate how far out from the center the electric waves can go. Near the end of the platform is a Launch Star. There is also a Koopa Troopa whose shell can be used to break open the treasure chests to collect their contents.
Although it did receive an updated appearance, this saucer returns from the Battlerock Galaxy. The electric rods are red instead of green and can move. There are a lot of Spiky Topmen in it, and there are also many electric currents that block Mario's path. At the top is Topmaniac, waiting to be fought. Once he loses his stamina from being slammed into the electrical rails of the arena he is fought in, Topmaniac relinquishes a Power Star.
- In Battlestation's Purple Coins, there is a trap in the form of a hidden Sling Star at the end of the moving platforms section, just after the Launch Star. It leads to the end of the level, but without collecting the final Purple Coin. It is only there so that people can attempt to get a score of 0 Purple Coins on the level.
- When it is featured in Mission 3: Revenge Of The Topman Tribe, The Starting Planet in this galaxy resembles the UFO Bowser uses to remove Peach's Castle from its foundation and into outer space in the opening cutscene.
- Several elements of this galaxy were reused in Super Mario Galaxy 2's Space Storm Galaxy.