Star Bit

"Hey, you! Yeah, you! Got any tasty Star Bits?"

- Hungry Luma

Star Bits are collectible and most common items in Super Mario Galaxy and Super Mario Galaxy 2. For every 50 (Super Mario Galaxy) or 100 (Super Mario Galaxy 2) Mario collects, he receives an Extra Life. If Mario loses a life while in a stage, his coins will disappear when he respawns, but his Star Bit count will remain the same. After completing a mission, Mario's Star Bits are added to his total amount. The stored Star Bits are then used to feed the Hungry Lumas found in the Comet Observatory and several galaxies to unlock galaxies and planets, respectively, or at various points in the different Worlds and to spin Chance Cubes on Starship Mario in Super Mario Galaxy 2. They can also be used to feed all other Lumas, without any gain.

Star Bits come in many colors (red, yellow, green, blue, purple, and white), and are quite shiny. They are first introduced when Mario arrives at Princess Peach's Castle at the beginning of the game, in the form of small rocks from space landing and releasing them. To collect them, the player can move the Star Cursor over them or simply run up to them.

When Mario flies through space from a planet to another planet, Star Bits often appear around him. To get them, the player must act quick and touch each of them with the Star Cursor before Mario lands on the next planet.

Star Bits are the Lumas' favorite food. When fed a certain number of them, a Hungry Luma will transform into a new planet or small galaxy and it will leave behind a pink Launch Star.

Pressing the button will shoot a Star Bit at the Star Cursor. This can be used to stun or defeat enemies. If a player holds the button, Star Bits will be shot continuously. Fired Star Bits cannot be recovered afterward.

The average enemy, such as a Goomba, will expel three Star Bits when defeated. However, that will only happen if the Star Spin is used, as simply jumping on one produces a single Coin. This holds true for most, but not all enemies. For example Magikoopas only release Coins no matter what method they are defeated by.

Mario can also make Star Bits appear by Ground Pounding certain buttons or activating Flipswitch Panels in various galaxies. Note that this will not always happen, as each button or Flipswitch Panel performs a different function depending on its galaxy and location.

There is a larger object thought to be somewhat related to Star Bits called the Star Crystal, many of which are normally seen in Launch Star paths. They are broken upon impact and produce at least six Star Bits that Mario must collect quickly before they fly away.

Mario Kart Wii
Star Bits appear in Rainbow Road, in various parts of the track. They are absent in split-screen mode, most likely a change to preserve frame-rate.

Mario & Sonic at the Olympic Winter Games
Star Bits also appeared in Mario & Sonic at the Olympic Winter Games, in the Dream Ski Jumping event, which takes place in the Good Egg Galaxy. They add points to the player's score.

Super Mario 3D World
Star Bits also appear in Super Mario 3D World. Here, they appear in the background of all special worlds (Star, Mushroom, Flower, and Crown), serving no real purpose.

Super Smash Bros. for Nintendo 3DS / Wii U
Star Bits are used as Rosalina's side special move in Super Smash Bros. for Nintendo 3DS / Wii U, which is called Star Bits. When used, Rosalina commands the Luma to shoot a small number of Star Bits. It is a long-ranged attack that cannot be absorbed or reflected, thus not making it a projectile attack. Nothing will happen if a Luma is not present when Rosalina uses this move.

The move has two variations that can be swapped out once the player unlocks them. Floaty Star Bit is a large Star Bit that is slow and gets in the way of fighters. Shooting Star Bit shoots only one Star Bit, but has longer range and more power. Unlike the default variation, these two variations are considered projectiles, and can be reflected or absorbed.

Mario Party 10
Star Bits make their first appearance in a Mario Party game in Mario Party 10. They appear in amiibo Party in the Rosalina Board. They act like regular Coins, in which they must be collected to get coins.

Trivia

 * In Super Mario Galaxy and Super Mario Galaxy 2, if 9,999 Star Bits are collected, all coconuts in the games will become watermelons permanently, even if the Star Bit amount drops below 9,999 again.
 * If the player has 777 or 7777 Star Bits on hand while on Starship Mario, Lubba will remark on how lucky that is, which is a reference to the saying, "Lucky 7". He also has messages for having 9999 and multiples of 1000 of them on hand as well.
 * Star Bits are modeled after the Japanese centuries-old candy Konpeitō, that is primarily made from sugar.
 * In Rosalina's Storybook, Star Bits are said to taste like honey.