Power Star

Power Stars are collectible items that can grant Mario access to more levels in-game (like Flagpoles from the original Super Mario Bros. and the New Super Mario Bros. series), unlike the similar-looking Super Stars, which only give brief invincibility. In Super Mario 64, Super Mario Galaxy, and Super Mario Galaxy 2, when the star for any given level has been collected, playing the level again will turn the Star into a translucent version of itself (similar to how Star Coins work). This Star can be collected, but it will not add to the player's total Star count. In all, there are 604 Power Stars (or 634 if Super Mario 64 DS is accounted for) in these three games combined. In Super Mario Sunshine, Shine Sprites take their place.

Super Mario 64 / Super Mario 64 DS


In Super Mario 64 and Super Mario 64 DS, Power Stars are spread throughout the worlds, and Mario (along with Yoshi, Luigi, and Wario in the Nintendo DS remake) is sent to go find them all. There are six Power Stars (seven in the DS remake) to collect in each world, and after finding 70 of them (or 80 in the DS remake), Bowser can be defeated. There are 120 Power Stars total in Super Mario 64; this was increased to 150 in the DS version due to 15 extra Secret Stars and 15 additional course stars. Super Mario 64 actually has a total of 121 (151 in the DS remake) Power Stars to be collected, if one counts the Giant Power Star. Since the original game never saves when Mario collects it, the total can only go up to 120, while in the Nintendo DS remake the game is, indeed, saved after collecting it, but the star is not added into the count (keeping the count on 150). There are also Silver Stars, which aren't as powerful as regular Power Stars; five Silver Stars are equal to one Power Star, and they combine to form one once they are all collected. In the multplayer mode of Super Mario 64 DS, stray Power Stars can bounce non-stop, similar to dropped Silver Stars in the same game, a trait that is shown only in this game.

Super Mario Galaxy
Power Stars make a return in the Wii game Super Mario Galaxy, where there are a total of 121 stars to collect for each Mario and Luigi (for a total of 242).

There are four types of Power Stars: First, there are regular Power Stars which serve the same purpose in other 3D Mario games. The second kind is the three Green Power Stars that, in addition to acting as normal Power Stars, unlock the Green Launch Star in the Comet Observatory which leads to the Trial Galaxies. The third type is the Red Power Star. There is only one; it appears in the Super Mario Galaxy mission "Gateway's Purple Coins". Last are the seven Grand Stars, the first of which, and the only one obtained without a boss fight, is the first star in Gateway Galaxy. Subsequently, the other six Grand Stars are each collected by beating Bowser or Bowser Jr.. These power up the Comet Observatory and unlock new Domes to explore. Silver Stars also return from Super Mario 64 DS, working in the same way, though they float alongside Mario once collected, and can't be lost by taking damage.

In Hurry-Scurry Galaxy as well as the planet that appears in Sea Slide Galaxy when the Hungry Luma transforms in the third mission, collecting Rainbow Notes turns the black hole into a Power Star.

Super Mario Galaxy 2
In Super Mario Galaxy 2, Power Stars play the same role as in Super Mario Galaxy. There are 242 Power Stars in total (116 normal Power Stars, 6 Grand Stars, and 120 Green Stars). If the Cosmic Spirit is used to complete a mission, the star collected will be a Bronze Star instead of a gold one.

Super Mario 3D World
While Power Stars themselves do not appear in Super Mario 3D World, the Green Stars work similarly, unlocking levels should enough be collected.

Mario Pinball Land
Power Stars reappear in the game Mario Pinball Land, working just like they do in Super Mario 64, obtained after completing certain trials, such as defeating a boss or a certain number of enemies in time, and their use is to make Mario's way to Bowser. At the end, the number of Power Stars obtained determines how much the point bonus is worth.

Super Smash Bros. for the Nintendo 3DS / Wii U
A Power Star appears in Rosalina's Final Smash in Super Smash Bros. for Nintendo 3DS / Wii U.

Captain Toad: Treasure Tracker
Power Stars reappear in Captain Toad: Treasure Tracker, appearing at the end of each stage. However, the game does not count Power Stars, treating them more as Goal Poles in that they only serve to be the end of the level.

Trivia

 * In both Super Mario Galaxy and Super Mario Galaxy 2, the shadows of Power Stars when they hover over the ground are shaped like a circle, while the shadows of Grand Stars are shaped like a Grand Star viewed from the top down.