Gameplay will be similar to that of the first Super Mario Galaxy, with a focus on platforming based on and around 3D planets (referred to collectively as galaxies)[7] with varying sizes and landscapes. The planets will also be smaller, allowing the player to jump from planet to planet more often. Mario will be able to ride the dinosaur Yoshi, who can use his tongue to swing across gaps, as well as eat fruits that give him various powers, such as speed boosts, the ability to inflate like a balloon, or the power to reveal secret paths.[8] While the player retains the ability to collect Star Bits with the blue Star Pointer from the first game, the Star Pointer is replaced by a red dot when riding Yoshi, which allows the player to aim and control his tongue.[9] This can be used for swinging off objects, pulling levers or, as in previous games, swallowing enemies and spitting them out.
Some of the mechanics introduced in Super Mario Galaxy will return, such as blue Pull Stars, sections restricting movement to a 2D plane, balance ball levels, and gravity-reversing background arrows. Power-ups such as the Bee, Boo, and Spring Mushrooms will also be returning, along with the Launch Stars and Sling Stars for interplanetary navigation. Also, new items and gameplay mechanics have been showcased since the game's unveiling at E3 2009. These include a drill that allows the player to drill through planets; the Rock Mushroom, which allows the player to smash through barriers;[10] and the Cloud Flower, which allows the player to create new platforms in midair.[11] The game also allows a second player to control an orange Luma to assist Mario. As well as collecting Star Bits for the player, the orange Luma can attack enemies and collect items such as coins and bubbles, holding on to them until Mario needs them.[12]
Instead of the hub world of the last game, Galaxy 2 will include a map system similar to those in Super Mario Bros. 3, Super Mario World, and New Super Mario Bros. Wii.[13] This is navigated via a mobile planet called Starship Mario (so named because it's shaped like Mario's head), which can be visited anytime and is expanded upon when new abilities are unlocked.[14] Completing levels unlocks new stages, but certain areas cannot be accessed until the player has collected a certain number of Power Stars. Players can also collect Comet Medals hidden in the stages to unlock harder levels with tougher challenges.[15] Similar to New Super Mario Bros. Wii's 'Super Guide' feature, Galaxy 2 has a 'Cosmic Guide' feature that lets the computer play through a section of a level if players are having difficulty. However, if players use this, they will only receive a Bronze Star upon completion, requiring them to complete it themselves in order to earn a Power Star.[12] There are also monitors that show hints to the player.[16] As in Super Mario Galaxy, Luigi is also a playable character, unlocked whenever Mario can locate him in a level
