Super Mario Galaxy 2 was met with critical acclaim, and was considered to match or surpass its lauded predecessor, with its creativity, level design, gameplay, music, and technological improvements over the original receiving high praise, although critics were divided on its lack of story and high difficulty compared to the original.

The game retains various gameplay mechanics introduced in the original, such as the blue Star Pointer that allows the player to collect Star Bits and shoot them at enemies, levels that restrict movement to a 2D plane, balance ball levels, and gravity-reversing background arrows.

[8] This is navigated via a mobile planet called Starship Mario[7] that serves as a hub world, which can be visited anytime and is expanded when new abilities or levels are unlocked.

These levels, containing Green Stars that are hidden or placed in hard-to-reach areas, require intense exploration and precision and may cause instant death if the player fails.

[10] Most of the levels in Super Mario Galaxy 2 offer a unique task based around its theme, and many focus on dynamic environments that change or alternate between various states.

For example, some environments change to the beat of the background music, such as sudden shifts in the direction of gravity or the appearance or disappearance of platforms; and others feature a special switch that temporarily slows down time.

[11] In addition, Prankster Comets have become more general and offer any number of variations: while Super Mario Galaxy offered only five mutually exclusive variations, the Prankster Comets in Super Mario Galaxy 2 range to any number of challenges that often mix or overlap.

As a result, both the dynamic environments and the Prankster Comets often create challenges with puzzle elements, requiring precision and strategy in order to overcome them.

[14] Yoshi can also use his tongue to swing across gaps, pull levers, and swallow berries and enemies (with the option to spit the latter back out as projectiles).

[17] There are also monitors called "Hint TVs" that will demonstrate how to perform a specific move or optimal ways of using a power-up.

On his way to Peach's castle, Mario finds a lost Baby Luma, who immediately befriends him and grants him the ability to spin.

Shortly thereafter, Mario's nemesis Bowser, who has grown to an immense size after abusing the power of the Grand Stars, attacks the castle.

He offers to grant Mario temporary ownership of the spaceship in exchange for him bringing back more Power Stars.

After traveling through various galaxies throughout the universe collecting Power and Grand Stars, Mario and his allies finally reach Bowser's giant starship generator, which is draining energy from what appears to be a comet.

The game ends with Starship Mario flying above Peach's castle, with the Comet Observatory streaking across the sky.

After Nintendo completed Super Mario Galaxy, Shigeru Miyamoto approached the development team and suggested that a follow-up be produced.

The idea however was nixed by Miyamoto who stated that Pikmin characters wouldn't work within the Mario universe, and that there was no reason for other such cameos.

[23] Miyamoto compared Super Mario Galaxy 2 to The Legend of Zelda: Majora's Mask, in that both games use the same engines as their predecessors, yet build upon their foundations.

[30][31] The Japanese, European and Australian versions of the game came packaged with an instructional DVD manual, explaining the basic controls, as well as showing advanced play.

However, as the game evolved, the sound team, headed by Mahito Yokota, realized they needed new music that fit with the new gameplay mechanics that were being added.

The orchestral performances were conducted by Taizo Takemoto, renowned for his work with the Super Smash Bros. Concert in 2002, while Kondo served as a supervisor, while also contributing five pieces to the soundtrack.

It has an average critic score of 97% at GameRankings and 97/100 at Metacritic, making it one of the highest-rated games on the sites alongside its predecessor.

[41][42] Tom McShea from GameSpot called it a "new standard for platformers", giving it a perfect 10, making it the seventh game in the site's history to earn that score.

"[49] Giant Bomb's Ryan Davis particularly praised the improved level designs, commenting that the designers were "bolder" and "more willing to take some weird risks with the planetoids and abstract platforming that set the tone in the original Galaxy",[62] while Chris Kohler from Wired commented that the level concepts alone "could be made into full games on their own".

[64] Despite this praise, some critics raised complaints over increased difficulty and the game's similarity to the original Super Mario Galaxy.

[47] However, Worthplaying editor Chris DeAngelus praised the game's difficulty, stating that "there are very few sequences where death will feel like a result of bad design instead of player error, which helps keep the frustration down".

[48] Kohler acknowledged that the reduced focus on story "was done with the intent of keeping things laser-focused on the gameplay" but mentioned that "Galaxy showed that the Mario team has some genuinely solid storytelling ability, and they implemented it in a way that didn't distract from the gameplay" and that "in this case it feels like a waste of talent.

As of December 2010, IGN awarded Super Mario Galaxy 2 the number 1 Wii game, overtaking its predecessor.