Super Mario Galaxy 2

Super Mario Galaxy 2 is a 3D action platformer game released for the Wii on May 22, 2010. It is the sequel to the 2007 game Super Mario Galaxy and is the fourth 3D platformer entry in the Mario franchise; it is also the first, and thus far, the only 3D platformer in the Mario franchise to be released on the same console as its predecessor (Super Mario Galaxy 2 was released on the Wii; the same console that Super Mario Galaxy was originally released for). The sequel retains many elements from its predecessor, such as the adventure being in outer space, the element of gravity, and recurring objects such as Launch Stars and Sling Stars. Returning items include the Bee Mushroom and the Fire Flower. However, the game introduces new elements as well, such as the utilization of Yoshi, new power-ups like the Cloud Flower, and the use of a guide within the game for beginner players. All releases of the game except for the American version include a beginner's DVD to help players understand the controls and items if they have not played Super Mario Galaxy. In North America, help for beginners is found on the official website as well as on the Nintendo Channel.

Super Mario Galaxy 2 is also the first Wii title to be digitally re-released on the Wii U's Nintendo eShop service.

Story
From the instruction booklet Shining stardust falls on the Mushroom Kingdom once every hundred years. That time had come again...


 * Dear Mario,


 * Would you like to share some cake while we watch the shooting stars? Meet me at the castle!


 * Peach

Mario ran through the field with stars falling around him. Suddenly, he noticed a strange light in the grass. As he peered cautiously through the reeds, he saw a small, lost Luma. With the baby Luma tucked safely under his cap, Mario rushed on to the castle. But when he got there, something unexpected was waiting for him… Super Mario Galaxy 2 is "another story of stardust". The game begins at the time of the Star Festival, which only happens every 100 years. Princess Peach invites Mario to share some cake while watching the shooting stars. On his way to Peach's Castle, Mario finds a lost Baby Luma, who seems to like Mario and jumps into his hat, granting him spin power. Near the castle, Mario discovers it under attack by Bowser, now gigantic thanks to the Power Stars, who kidnaps Peach and takes her away to the center of the universe. In response, Lumas who crashed near the castle offer to aid Mario to chase Bowser by transforming into a Launch Star and launching Mario to space.

After collecting a Power Star, Mario arrives on a planet-like object, where he meets Lubba, who tells him that his crew and their spaceship were attacked by Bowser. Realizing both him and Mario need each others' help to collect the stolen Power Stars and rescue Peach, he uses the Power Star to fix his ship and transform it into Starship Mario, which is used to travel through space and find more Power Stars. During his travels, Mario has to deal with Bowser's forces, including Bowser Jr. and Super Bowser himself.

Finally, Mario and friends locate Bowser's Galaxy Generator, where Bowser is fought for the final time. After Bowser's defeat, his empire becomes undone, and Peach is saved. A comet which was caught by Bowser's fortress is also freed and is revealed to be the Comet Observatory. Rosalina then appears, happy to see that Baby Luma is safe. Baby Luma, overjoyed that he's reunited with his "mama", heads back to his home, and takes Mario's cap as a souvenir, much to Mario's surprise. After the Comet Observatory leaves, Mario and Peach return to their own home using the Starship Mario. Along the way, Bowser is shown in a tiny form near Peach's Castle.

If the player collects the first 120 Power Stars and battles Bowser again in his fortress, an extra scene is shown after the credits, revealing Rosalina and her Lumas in the Comet Observatory's Library. She has finished reading a story to them (possibly the events of the game itself) and plans on telling the Lumas a new story about the Green Power Stars. A new feature is then unlocked in which all the galaxies are visited by green Prankster Comets. From there, the player must hunt down all the Green Stars. When they are all collected (adding up to 240 Power Stars), the Grandmaster Galaxy is opened in World S. It houses the last two Power Stars, and when the last one is reached, Rosalina congratulates the player and appears on Starship Mario.

Gameplay elements
The gameplay is similar to Super Mario Galaxy, with a focus on platforming based on and around 3D planets of varying sizes and with many different types of surfaces. Power-ups, such as the Bee Mushroom, Boo Mushroom, Spring Mushroom, and Fire Flower make a return, along with new ones such as the Rock Mushroom and the Cloud Flower, as well as various enemies and Airships. Launch Stars reappear for interplanetary navigation, along with a Luma and Mario's spin action. Additionally, the concept of "dark matter" appears as the medium of which Cosmic Clones are composed, and as a portal through which Airships emerge. 2-D stages featured in Super Mario Galaxy are also included in Super Mario Galaxy 2, introducing many new features. The game has only three file slots to use, unlike the six files in the preceding game; also, files can no longer be copied.

Mario is controlled with the analog stick and can jump with the. The works just as the  trigger did in Super Mario 64. The player uses it to make Mario crouch, do Somersaults, and do Long Jumps. The centers the camera behind Mario, while the  can adjust the camera angle manually. By pressing the upper part of the, the player can enter a first-person perspective.

The game also uses the motion sensors in the Wii Remote. The pointer of the Remote appears as the Star Pointer on the screen. The Star Pointer is used to perform a variety of actions, such as using Pull Stars, manipulating Sling Pods, and collecting Star Bits. Shaking the Wii Remote or Nunchuk makes Mario perform a spin.

One of the more notable additions in Super Mario Galaxy 2 is the inclusion of Yoshi. When Mario finds a Yoshi egg, he can crack it to release and use Yoshi. Yoshi changes colors when eating either a Dash Pepper, Blimp Fruit or Bulb Berry; a Dash Yoshi darts at rapid speeds, a Blimp Yoshi inflates and floats upwards, and a Bulb Yoshi lights up and shows hidden paths for a certain amount of time, respectively. When utilizing Yoshi, the player's Wii Remote cursor turns into a red sphere that detects targets for Yoshi's tongue. Using the cursor allows Yoshi to swallow enemies and swing from special flowers.

Elements from older games are also included in the new game. These elements include a remix of Super Mario Bros.'s overworld theme (which is originally heard in Toy Time Galaxy from the predecessor, Super Mario Galaxy), Supermassive Galaxy, a galaxy that is reminiscent of Giant Land from Super Mario Bros. 3, a remix of the second overworld theme from Super Mario World, the Checkpoint Flag from New Super Mario Bros. Wii, Throwback Galaxy, a galaxy based on Whomp's Fortress from Super Mario 64, and a remix of the main theme and slide theme from Super Mario 64.

Like Super Mario Galaxy, Super Mario Galaxy 2 features a main hub. For traveling between different galaxies, Mario uses a planet shaped like his head, Starship Mario. Starship Mario can be explored, much like the Comet Observatory, although it is smaller. The game has a total of 242 stars to collect, twice the number of stars found in Super Mario Galaxy, including 120 Power Stars, 120 Green Power Stars and an extra 2 Power Stars in Grandmaster Galaxy.

Multiplayer from the original Super Mario Galaxy reappears, but in addition to being another star pointer, the second player is a Co-Star Luma. The second player can stun enemies and pick up Star Bits like in Super Mario Galaxy, but now they can pick up coins (including Purple Coins) and mushrooms, defeat enemies by spinning, stop the Star Ball (while player 1 is riding on it), activate checkpoints, and flip switches.

Super Mario Galaxy 2 features ways to help players during gameplay similar to the Super Guide mode seen in New Super Mario Bros. Wii. In some levels, the player may watch the Tip Network, which is a short demonstration of Mario taking some actions to progress. Another way the game offers is the Cosmic Guide mode. If the player finds a very difficult obstacle on their way, an entity known as the Cosmic Spirit asks Mario if he needs some help. Activating this mode, Mario passes automatically through the level to find the Star. The player may stop this mode by pressing the, though once the player has chosen this mode, they finish a level by getting a Bronze Star instead of one gold. The player must play through the level without the Cosmic Guide to gain a gold Star.

Unlike in Super Mario Galaxy, the player can now switch between playing as Mario or playing as Luigi in certain levels. If the player clears Bowser's Galaxy Generator, Luigi can be played as in any level. Like in most Mario games, Luigi can jump higher but has reduced traction.

Controls

 * Move
 * (shake): Spin
 * Jump / Interact / Swim (while underwater) / Stun enemies and grab coins and items (P2 only)
 * Shoot Star Bit / Lick objects and enemies (when on Yoshi)
 * Crouch / Ground Pound (in midair) / Dive (while underwater)
 * Enter/exit first-person view
 * Rotate camera left/right
 * Pause

Setting
Super Mario Galaxy 2 is set in outer space. With the exception of the prologue that is staged in the Mushroom Kingdom, all levels – referred to as "galaxies" in this game – occur on distant, off-world lands. A galaxy is a cluster of planetary objects and other celestial bodies that can be traveled between. Most of these objects have their own gravitational pull. This prevents Mario from falling off their edge and mitigates the chances of the player getting lost. There are few walls or ceilings on the planets to obstruct Mario's path, and if he keeps moving forward in one direction, he returns to his starting position. Most planets are spherical or at least have rounded edges to complement this concept. Not all planets are structured like this: some are structured like traditional Super Mario courses and have their center of gravity below their mass.

Many galaxies take place on two-dimensional planes and Mario's movement options are restricted accordingly (i.e. when Mario is on a 2D side-scrolling plane, the player cannot tilt towards the z-axis to make him fall off the side). There are galaxies entirely on 2D planes, but also ones that feature both 2D and traditional 3D segments. They are usually restricted to specific planets and conveyed through environmental context. Many galaxies feature switches mounted into the landscape that change the entire level when interacted with. Some shift between the gravity being pulled from the floor and ceiling. Others slow down time, or shift placement when Mario spins.

The theme of space is more subdued in Super Mario Galaxy 2 than it is in its predecessor. While there are galaxies that feature skyboxes with nebulas and stars, the most recurring backdrop is a blue sky with fluffy clouds. However, the game does convey the outer space setting in ways distinct from the first Super Mario Galaxy. As Starship Mario, the game's hub, travels through space, it passes asteroid belts, falling stars, and black holes. Lumas, star children introduced in its predecessor, appear in nearly all galaxies and on the hub. The game's thematic core is surreal and whimsical. Rather than resemble a spacecraft, the hub is a grassy planetoid shaped like Mario's head and has a wooden bow like a seafaring vessel. Gulls fly alongside the ship, as if it were on the open ocean. The whole game is framed from the perspective of an unseen narrator reading a storybook to the player, and many locations have elements. A pair of robots have tea together in a garden on Starship Mario. Several galaxies resemble topiaries and dollhouses. Some planets look like wooden blocks, candies, clouds, and musical instruments.

According to producer Shigeru Miyamoto, the integration of 2D levels derived from a desire to make Super Mario Galaxy 2 more accessible and less daunting to players inexperienced with 3D platformers. Integration of elaborate switch elements bore from the desire to differentiate Super Mario Galaxy 2 from its predecessor similarly to how The Legend of Zelda: Majora's Mask (2000) was differentiated from Ocarina of Time (1998). Many elements not present in the first Super Mario Galaxy  informed the setting of the courses that feature them. For example, the first galaxy to feature the Spin Drill item, Spin-Dig Galaxy, visually alludes to construction sites and has enemies that tunnel through soil.

Galaxies
In Super Mario Galaxy 2, levels are accessed linearly within worlds. This is a departure from the proceeding 3D Super Mario games and is comparable to the 2D ones. The player accesses worlds from the Starship Mario, a small planetoid that serves as the game's hub. When Mario steps on a panel on the starship's bow, the perspective rapidly pans out to a view of the current world. Starship Mario – itself shaped like the protagonist's head – is a stand-in for Mario himself that can be moved between galaxies like a cursor. Galaxies are unlocked unilaterally – collecting a Power Star within one opens up paths to the nearest galaxies. Except for World S, the final galaxy of each world is a boss galaxy that features a fight against Bowser Jr. or Bowser. Defeating them unlocks the following world. The earliest worlds have the simplest, most straightforward paths between galaxies, but the paths become more divergent with each world, enabling the player to visit galaxies in whatever order they want (see right).

Unlike proceeding games that feature worlds – like Super Mario Bros. 3 (1988) and New Super Mario Bros. (2006) – the galaxies within the worlds of Super Mario Galaxy 2 are not thematically unified. For example, World 3 contains galaxies themed around forests, snow, and haunted houses. While not all galaxies need to be completed, no numbered worlds can be skipped over to reach the end credits.

Each galaxy contains objectives called missions. Completing a mission has Mario obtaining one of the galaxy's Power Stars. One mission correlates with one Power Star. The structure of missions is closely derived from the first Super Mario Galaxy (2007). However, there are fewer dedicated missions in individual galaxies, with none having more than three. By contrast, the most robust galaxies in Super Mario Galaxy have as many as six missions. Some missions have one or more hidden Green Stars that begin to appear once the player has collected 120 normal Power Stars. Like regular Power Stars, collecting one is considered as the end of the mission. Grandmaster Galaxy is the only course in the game to lack any Green Stars. Combined, there are 242 collectible Stars in the game, the same number in its predecessor.

Some galaxies can only be unlocked by feeding Hungry Lumas a requested number of Star Bits. They appear on the world map and transport to the Starship Mario when touched. There is one in every world. Hungry Lumas appear within galaxies too, but these individuals eat coins instead of Star Bits. Feeding one the requested amount causes it to transform into a planet that contains a Secret Star. Secret Star missions are otherwise unlocked by completing certain criteria. Doing so causes non-playable characters to write letters to Mario requesting his help or to challenge him in specific galaxies he has already visited at least once. The most recurring writer is The Chimp, a monkey from Fluffy Bluff Galaxy who considers Mario to be his rival.

After Mario has collected 30 Power Stars and completed "Bowser's Big Lava Power Party", his brother Luigi begins to appear in some galaxies and offer to collect the Power Star for him. Selecting "yes" allows the player to control Luigi for the mission until it is completed or exited. Completing the mission as Luigi unlocks a staff ghost for the galaxy. When followed, it leads the player towards hidden items or Secret Stars. Once "Bowser's Fortified Fortress" is completed, Luigi becomes permanently accessible via a room on Starship Mario's stern and can be played as in any level.

Super Mario Galaxy 2 is the first 3D Super Mario game to include a dedicated secret world accessible only after completing the main story, similar to the Special Zone of Super Mario World (1990) or World 9 of New Super Mario Bros. Wii (2009). Called World S, this world contains several galaxies based around planets from the first Super Mario Galaxy that have been modified in ways that make them more challenging.

There are 49 galaxies in the game. There are 50 if Starship Mario is included. The chart below lists the galaxies in the order that they appear on the Star List. The galaxies are separated and color-coded according to the world they occur in. Each galaxy is given a brief description, an in-game screenshot, and a list of its missions. The descriptions come from the official Prima Games guide for Super Mario Galaxy 2. There is a legend at the bottom of the chart that details what the symbols used in it represent.

Prankster Comets
Comet Medals are collectibles hidden in galaxies. Every galaxy has a Comet Medal. Collecting one adds it to the player's total, much like Power Stars, Star Bits, and coins. If Mario loses a life after collecting one and finishes the mission, the Comet Medal will not be added to his total. He will have to return to a mission in that galaxy to collect it again. Accumulating Comet Medals causes Prankster Comets to orbit previously visited galaxies. The comets unlock new missions in their corresponding galaxies with unique attributes, namely speed runs; "daredevil" runs (in which Mario is defeated if he takes a single hit); Purple Coin runs; races against Cosmic Clones; romps requiring Mario to defeat 30 enemies within a time limit; and missions where the speed of obstacles is increased. Not every galaxy can be orbited by these types of Prankster Comets. After completing all 120 missions and completing "Bowser's Fortified Fortress" a second time, Green Comets begin orbiting every galaxy except for Grandmaster Galaxy. This causes hidden Green Stars to appear in previously completed missions.

Prankster Comets were an element in the game's predecessor, but their integration has been simplified in Super Mario Galaxy 2. Additionally, unlike in the prior game, Prankster Comets permanently remain in orbit around their corresponding galaxies, allowing the player to access the new missions at any time they wish.

Starship Mario
The Starship Mario is the hub of the game. It is a planetoid-turned-spaceship created by Lubba as a home for his Lumas. After becoming acquainted with Mario, he transforms it into his likeness. Rather than invoke a spaceship design comparable to those in science fiction, the Starship Mario has a fantastical design: it has a bow like a seafaring vessel, a stone chimney, and is flocked by sea gulls. It is covered in flowers and has a small brook. It has two accessible rooms: one is the Engine Room that houses the beacon – the source of energy for Starship Mario. The other is a pipe room occupied by Lumalees accessible via a pipe in the starship's left ear. It only appears after Mario has collected a Power Star in World 3. The bow of Starship Mario has a button before a steering wheel that allows the player to access the world map and move the starship like a cursor. After collecting sixteen Power Stars, Lubba places a Totals Sign to the left of the helm that outlines all of the Power Stars and Comet Medals that the player has collected. Lubba himself is to the right.

A grassy platform with fruits begins orbiting the starship after completing "Saddle Up with Yoshi", and a Starshroom bearing members of the Toad Brigade flies with it after completing "Digga-Leg's Planet".

In Super Mario Sunshine and Super Mario Galaxy, completing missions would cause portions of their respective hub worlds to become illuminated. This gave the player a passive visual indication of progress and an indicator as to where one can go. In Super Mario Galaxy 2, this is instead achieved by filling up the Engine Room and in having non-playable characters board the Starship Mario as passengers. The Engine Room is accessible under the stone brim of the starship's cap. Most power-ups will be put on display here after Mario has encountered it in a mission. The only exceptions are the Cloud Flower and Yoshi egg, which instead appear on the exterior of Starship Mario and can actually be used. The power-ups in the Engine Room are only for display. The Spin Drill is among them despite functioning as a held item.

The passengers that board the Starship Mario represent the various people and characters encountered in the galaxies. Some passengers will board once they are met in a mission, but others have more specific criteria required (see below). The more the player completes of the game, the livelier the Starship Mario becomes with characters and the more elaborate its music becomes – elements shared with the Comet Observatory in Super Mario Galaxy. The passengers will share tricks on level progression or actions when prompted. Some allude to late-game secrets. The last passenger – Rosalina – is the final unlockable of the game. Piantas are the only people to not have a representative on the Starship Mario. The passengers and the criteria needed for them to board is outlined below.

Non-playable characters
A star symbol (★) denotes a character that was not in the first Super Mario Galaxy.

Returning enemies
A star symbol (★) denotes an enemy introduced in a prior Super Mario title but was not in the first Super Mario Galaxy.

Power-ups
The Ice Flower and Red Star are the only power-ups from the first Super Mario Galaxy to not return.

Gameplay

 * While swimming underwater, Mario and Luigi can no longer spin rapidly.
 * An exploit that allowed Mario to climb up slopes was patched.
 * The game now saves automatically instead of the player having to manually save after every Power Star collected.
 * If the player gets a Game Over, they return to the hub world, rather than all the way back to the title screen.
 * There are only three save files instead of six.
 * Rosalina and Luma are new save file icons, while Luigi can be used as an icon from the start.
 * The player cannot copy save files like in the previous game.
 * Bugaboom's boss fight now uses the Cloud Flower and springs, rather than the Bee Mushroom and swinging flowers.
 * Coins are now a general collectible like Star Bits, rather than just being collected for a high score. After collecting a Power Star, coins collected are added to the coin collection, similar to Star Bits.
 * Checkpoints are now marked by a Checkpoint Flag, rather than being invisible.
 * The game now records the time the player has taken to beat the level.
 * Luigi is now unlocked after defeating Bowser and unlocking World S, instead of the player playing through the game twice as Mario and Luigi.
 * Cutscenes are now done in a storybook format, and the player has to press a button to progress dialogue.
 * The game rewards a 1-Up upon collecting 100 Star Bits, rather than every 50.
 * Collecting a Life Mushroom while having a full six hit points now rewards a 1-Up rather than absolutely nothing.
 * When receiving a letter from Princess Peach, Mailtoad automatically gives the player 5 1-Ups, rather than asking if they want to accept it.
 * Luigi no longer receives 20 1-Ups from Peach's letters, only receiving 5 like Mario.
 * The credits are more interactive, with the player playing through various levels in the game, rather than having standard credits.
 * The first-person camera is able to turn 360 degrees rather than 90 degrees left and right.

Levels

 * In the first game, excluding green or red Power Stars, major galaxies had six Power Stars (three missions, two Prankster Comets with one of which being a Purple Comet mission, and a Hidden Star) while minor galaxies had one (the sole mission). In the sequel, these numbers were changed to give major galaxies three Power Stars and minor galaxies two Power Stars.
 * The type of stars each galaxy has now varies, rather than having a constant amount of each type per galaxy. Major galaxies have either two missions and a Prankster Comet, two missions and a Hidden Star, or one mission, Prankster Comet, and Hidden Star each. Minor galaxies have either one mission and a Prankster Comet, one mission and a Hidden Star, or two missions (with the second mission being a challenge from either The Chimp or Jibberjay).
 * Hungry Lumas that create planets in galaxies now require coins to be fed to them instead of Star Bits. However, Hungry Lumas that make galaxies still require Star Bits.
 * Hungry Luma galaxies can be accessed via the World Map, just like the rest of the galaxies in their corresponding world, rather than using an alternate method to access it (a launch star outside of the dome).
 * The galaxy icons on the World Map are much more detailed than in the first game, and some of them have more animated features, rather than being completely stationary models. Similar concepts have been used later in Super Mario 3D Land and Super Mario 3D World's stage icons.

Prankster Comets

 * Prankster Comets are no longer categorized by type, simply leaving them as generic Prankster Comets.
 * Boss galaxies now have Prankster Comets.
 * During Speedy and Purple Coin missions, the clock now stops after the star appears, whereas in the original, the clock ran until the star was grabbed.
 * Some Speedy Comet missions have clocks that must be grabbed to keep the timer going.
 * Cosmic Comets and Fast-Foe Comets do not return, being replaced by Clone Comets and Double Time Comets respectively.
 * The game now notifies a player when a Prankster Comet has appeared in a certain galaxy, rather than having to check themselves.
 * The player can select any mission in the galaxy they want even if a Prankster Comet is in orbit. Because of this, Comet Tico and its ability to move Prankster Comets do not return.
 * If the player loses a life during a Prankster Comet mission, the game does not ask the player if they want to retry the mission or return to the hub world, instead restarting the mission as normal.

Music

 * While many soundtracks return from the first game, some returning soundtracks have been remixed to be more orchestrated rather than maintaining synthesized instruments. This includes:
 * The theme of Bowser's Star Reactor and Bowser's Dark Matter Plant, used in Bowser's Lava Lair and Bowser's Gravity Gauntlet.
 * The theme of Honeyhive Galaxy and Gold Leaf Galaxy used in Honeybloom Galaxy and Honeyhop Galaxy.
 * The theme of Toy Time Galaxy used in Supermassive Galaxy.
 * The mission selection theme.
 * The level introduction theme.
 * The Power Star fanfare.
 * The jingle that plays when the player returns to the hub world.
 * The theme of the Baron Brrr and Undergrunt Gunner boss battle, used in the King Lakitu and Mandibug Stack battles.
 * When the star appears, the music changes to the soft "star appears" theme for the rest of the mission, unlike the original, which only played the theme after a boss was beaten.
 * When Mailtoad has a letter from Peach, there is no sound that constantly plays when the player is near him.
 * During the egg phase of Dino Piranha and Fiery Dino Piranha's boss fights, as well as the first phase of Major Burrow's boss fight, a new soundtrack is used during those sections instead of the originals.
 * The Mandibug Stack mini-boss now has an actual theme playing (which shares the same with King Lakitu), rather than using the same theme as the level.

Aesthetic

 * When Lumalee asks if the player wants to buy a 1-Up Mushroom or Life Mushroom, the dialogue boxes now show their names alongside their icon (like the Japanese version of the first game), rather than just their icon like in the English version of the first game.
 * In the American version of the game, when getting an extra life, the text now shows "1UP" like the Japanese version instead of "1-UP" like the English version of the previous game. However, it's still "1-UP" in the European version.
 * The "Game Over" text is now yellow instead of pink. The text is also slightly wider than in the previous game.
 * The first Star that the player obtains is a Power Star rather than a Grand Star.
 * The text saying "You got a Star/Grand Star" during the star collecting victory animation as well as the text saying "TOO BAD!" during when Mario/Luigi loses a life are slightly larger than in the first game.
 * When the player returns to the Starship Mario after obtaining a Grand Star, the text box that appears afterwards says "You got a Grand Star", instead of "You got a Star".
 * Similarly, when the player collects a Green Power Star, the text box says, "You got a Green Star", instead of "You got a hidden Star".
 * Fiery Dino Piranha's egg now has visible heatwaves around it.

General Producer

 * Shigeru Miyamoto

Producers

 * Yoshiaki Koizumi
 * Takashi Tezuka

Director

 * Koichi Hayashida

Music

 * Mahito Yokota
 * Ryo Nagamatsu
 * Koji Kondo

Development
The development of Super Mario Galaxy 2 started as soon as the first Super Mario Galaxy was released. Many of the ideas were based on those shown in the first game, which, for example, included moving or adding new stars in the levels. The project was initially called  Super Mario Galaxy 1.5. The development of the new version of the game lasted a year; however, Miyamoto realized that the new game was beginning to overflow with new elements and ideas. Therefore, the team decided to create a real Super Mario Galaxy sequel rather than a new version of the original installment. The development of the sequel then lasted two and half years.

The game was revealed at E3 2009, along with New Super Mario Bros. Wii. Although the game was far along in development, it was held back to 2010 due to the release of New Super Mario Bros. Wii in November 2009. According to Shigeru Miyamoto, 90% of the features in the game would be new, whereas the remaining 10% were already introduced or featured in the original Super Mario Galaxy. Shigeru Miyamoto noted, "Really what we ended up with is more than 90% of what you'll see in Galaxy 2 is brand new. I'd say closer to 95, maybe even 99%. One of the new things was the inclusion of Yoshi, and also the use of the drill to open up and drill through stages." On the other hand, Miyamoto stated in an interview that he wanted to go with as little story as possible for Super Mario Galaxy 2.

Some of the developers wanted to include characters from other Nintendo franchises, such as Pikmin or Donkey Kong. However, Miyamoto shot down the idea.

CEO of Nintendo America stated that Super Mario Galaxy 2 would be more challenging regarding its predecessor. It was hinted that the new game would implement a tool-assisted guide, similar to the Super Guide from New Super Mario Bros Wii. It was eventually confirmed, although it worked differently. Beginner players could use the Cosmic Guide mode (activated when encountering the Cosmic Spirit) or the Tip Network to learn moves and hints during gameplay. Japanese, European and Australian boxes came with a special DVD to help players to know basic and expert techniques of the game.

Reception
Upon its release, Super Mario Galaxy 2 was met with universal acclaim, and is one of the highest rated video games of all time on the aggregation sites Metacritic and GameRankings. EDGE magazine has given the game a perfect score of 10 out of 10, being the third Mario game so far to receive such rating (the others were Super Mario 64 and Super Mario Galaxy). Official Nintendo Magazine grants it a 97%, while Game Informer has given the game 9.25 out of 10. Nintendo Power gave it a 9.5 out of 10. IGN and Gamespot granted the game a perfect 10/10, as well as GamesRadar. Gamespot also gave the game the Best Platforming Award and the Best Wii Game Award of 2010. IGN named it the Best Wii Game of all time. Gametrailers has given a 9.7 from 10, while Famitsu a 37 out of 40. GamePro gave it four and a half stars, X-Play gave it a perfect five out of five stars, and 1UP.com an "A" rating.

Sales
Super Mario Galaxy 2 sold 143,000 copies on its first day of release in Japan and 340,000 copies in its first week. In North America, the game sold 650,000 copies during the month of May 2010. In the United Kingdom, it was the third best-selling game among multiplatform releases and the best-selling single platform release for the week ending June 26, 2010. As of July 16, 2010, the game has sold 1 million copies within the USA and 6.36 million copies worldwide as of April 2011.

Awards
Super Mario Galaxy 2 was awarded Game of the Year by Nintendo Power and named "Wii Game of the Year" by IGN, GameSpot, and 1UP in 2010. In the March 2012 issue of Official Nintendo Magazine, the publication named Super Mario Galaxy 2 the "Greatest Nintendo Game Ever Made" ranking at #1 out of 100. It was awarded Game of the Year and Best Game on Wii by Guinness Book of World Records Gamer's Edition 2011.

Quotes

 * "Oh, by the way, I found this 1-Up Mushroom a little while ago! Think you can use it?" - Banktoad
 * "Super Mario Galaxy, Wahoo!" - Mario
 * "First time in galaxy, always Comet medal somewhere. Look hard. Find!" - Whittle

Yoshi's infinite Flutter Jump
To perform this glitch, Mario should ride Yoshi and perform a Flutter Jump. When he is almost finished, the player should release and press, then, release  and hold , repeating this to gain more height. This was discovered by fans very shortly after the game's release. This glitch is known by many fans as "Infinite Fluttering," and has become the most well-known glitch in the game. Using this glitch, players can fight the final boss, Bowser, and also even clear the Perfect Run with Yoshi. It is also because of this glitch that many other glitches have also been found.

Flip-Swap Superjump
In the Flip-Swap Galaxy, Mario can use the upward momentum from a Red-Blue Panel flipping up to perform an extremely long, high jump. Mario must be on one of the non-flipping platforms in the galaxy. Then, he must run toward an empty space that a flipping platform flips to when Mario spins. Right before Mario runs into the empty space, he must spin to make the flipping platform flip to the empty space. Mario should fall onto the flipping platform while it is still rising. Finally, Mario must perform a Long Jump right before the platform stops moving. The timing for this is difficult, but if performed correctly, Mario does a "superjump" that covers huge distance and can be used as a shortcut.

This can also happen if Cloud Mario jumps immediately after he forms a cloud.

Pre-release and unused content
In the debut trailer from E3 2009 and the two Media Summit Trailers, there were several differences from the game's release.
 * The starting planet in Boo Moon Galaxy was originally going to look similar to the Crystal Planet in Space Junk Galaxy from the first game.
 * When a player used a Dash Pepper, the player did not glow or leave a glowing trail as in the final version.
 * Good Egg Galaxy's background was used in Tall Trunk's Slide, and in Space Storm Galaxy's Topman's tower.

Music
An official two-disc soundtrack was released exclusively to Club Nintendo members in Japan, which holds all seventy songs from the game. The game's official soundtrack is performed by the Mario Galaxy Orchestra.

References to other games

 * Super Mario Bros.: Supermassive Galaxy's music, which is itself a remix of Toy Time Galaxy's music from the first game, originated from this game's overworld theme. The first few notes of this music are played when switching between Mario and Luigi. Other music from this game returned from Super Mario Galaxy as well. In the Grandmaster Galaxy, there is a backdrop featuring elements and enemies, as well as Mario and Luigi in their 8-bit sprites from this game.
 * Super Mario Bros. 3: Supermassive Galaxy is similar to Giant Land from this game, as the two are of massive size and feature giant versions of common items and enemies.
 * Super Mario World: Yoshi, who first appeared in this game, is playable in Super Mario Galaxy 2, and the percussion sounds heard when riding on Yoshi are reused. In fact, when Mario first saves Yoshi, his speech is obviously based on his speech in this game. Additionally, this game's athletic theme returns as Hightail Falls Galaxy's music (as well as the music that plays during the mission for Starshine Beach Galaxy, "Purple Coin Beach Dash"), and the Ghost House theme returns as Haunty Halls Galaxy's and Boo Moon Galaxy's music. Also, the sound effect that is heard when a P Switch's effect is about to run out is used in the bonus areas of Super Mario Galaxy 2, and the sound effect heard when passing through a door in this game is used when opening a door in Boo Moon Galaxy. In Puzzle Plank Galaxy, the Rainbow Notes play the bonus game theme from Super Mario World.
 * Super Mario 64: The slider theme from this game is used for Tall Trunk Galaxy and Rolling Coaster Galaxy. The "Bowser's Road" theme is remixed once again, appearing in several Bowser-themed galaxies. Also, the Throwback Galaxy is a replica of Whomp's Fortress; its boss, the Whomp King, is fought there, and an arrangement of the course's music plays there as well. Both games start with Peach sending a letter to Mario involving cake. Additionally, the "Inside the Castle Walls" theme can be heard when rescuing Peach and the final Grand Star in Super Mario Galaxy 2. The Rainbow Star theme is remixed once again from the Wing Cap and Vanish Cap theme. Finally, Mario says, "Thank you so much for playing my game!" after the ending credits, just as he did in this game.
 * Super Mario Sunshine: The Starshine Beach Galaxy is based on some elements from this game. The main mission of Twisty Trials Galaxy is a replica of the secret level found in Episode 4 of Ricco Harbor. The red and blue flipping platforms return, although they work differently. A few of Yoshi's sound clips are reused from this game. Piantas also return.
 * Super Mario 64 DS: The Silver Stars from this game return in Super Mario Galaxy 2.
 * New Super Mario Bros. Wii: The Checkpoint Flag returns from this game, and the Cosmic Guide and Tip Network are based on the Super Guide and hint movies from this game, respectively. Also, the world maps are based on the one from this game. In both games, Bowser is giant, and the final battle is divided in two different parts, the latter having a bigger Bowser. The model for the Koopalings' cake reappears in Super Mario Galaxy 2's credits. Additionally, when players collect all the coins in a certain time limit that were accessed by a switch in Super Mario Galaxy 2, the audience claps in the same fashion they did in this game.

References in later games

 * Donkey Kong Country Returns: The Flip-Out Galaxy's concept is back (but slighty changed) for the Switcheroo level.
 * Super Mario 3D Land: Star Medals look similar to Comet Medals. In addition, the theme used on bonus planets is covered for Mystery Boxes. The blue and red flipping platforms return, but they are activated by jumping. The "beat blocks" return as well. Cosmic Clones return, but they look different. An early theme for the Boom Boom battle was the same theme played when fighting Peewee Piranha. Also, a lot of the voice clips, sounds, and enemy animations and behaviors are reused. World 7-5 is similar to Puzzle Plank Galaxy, and Special 5-1 is similar to Flip-Swap Galaxy. Also, a strange, ghostly entity can be seen in the woods near the Goal Pole of World 4-4, which bears resemblance to the three, strange, black Kodama-esque figures (Hellvalleyskytrees) seen in the background of Shiverburn Galaxy.
 * Mario & Sonic at the London 2012 Olympic Games: The Sky Station Galaxy (under the name "Synchro Battle Galaxy") appears in the Dream Spacewalk event.
 * Fortune Street: Starship Mario makes an appearance as one of the Mario series game boards.
 * Super Mario 3D World: Green Stars make an appearance, replacing Star Medals from Super Mario 3D Land. Fizzlits return, although in a more square-shaped appearance. The final boss themes (and the Meowser defeated fanfare) have portions of the themes for Bowser's Galaxy Generator. Also, Grumblumps have a similar appearance to Rhomps. The Beat Block mechanic returns under the name "Beep Block", and the Beep Block stages return to the "beep-beep-beep-switch" rhythm as in this game with the same tempo as the Beat Block Galaxy theme as well. There is additionally a level called Boss Blitz, which is in reference to the Boss Blitz Galaxy.
 * Super Smash Bros. for Nintendo 3DS / Wii U: Starship Mario appears in the background of the Mario Galaxy stage.
 * Mario Kart 8 / Mario Kart 8 Deluxe: The giant dragon used for the Dragon Driftway racetrack has a similar design to Gobblegut, but with legs. In Deluxe, the battle course Dragon Palace has two statues of the same Gobblegut-like dragons. In the Booster Course Pass DLC, the Rock Cup's icon is a Rock Mushroom.
 * Mario + Rabbids Kingdom Battle: Gobblegut is used as the base design for a weapon in this game.
 * Super Smash Bros. Ultimate: Rock Mario, Lubba, and Starship Mario appear as spirits using their artwork from Super Mario Galaxy 2. Also, Melty Monster Galaxy's theme is added to the Mario series track list.

Trivia

 * The save data description in English is "Launch into a new adventure!"
 * The Japanese equivalent is 「銀河を舞台にまたまた大冒険！」
 * Even though Super Mario Galaxy 2 is not featured in the compilation title Super Mario 3D All-Stars, an abridged version of the theme for when Mario or Luigi grabs a Power Star is recycled for the game's title screen.