Green Power Stars, or simply known just as Green Stars, are first found in Super Mario Galaxy.
Green Power Stars are shaped like standard Power Stars. Hence the name, they are colored green. In Super Mario Galaxy series, Green Power Stars add up to the Power Star counter.
Super Mario Galaxy series
Green Power Stars made their debut in Super Mario Galaxy. There are three, one in Battlerock Galaxy, Buoy Base Galaxy, and the Dusty Dune Galaxy. Once all three are found, the Trial Galaxies are unlocked.
The Green Power Stars will turn into Green Lumas that look over the Green Launch Star, located between the Garage and the Terrace|, that launches Mario to the otherwise unapproachable Planet of Trials, where three more Green Lumas await to transform into Launch Stars to send Mario to Rolling Gizmo Galaxy, Bubble Blast Galaxy, and Loopdeeswoop Galaxy, depending on which Luma he talks to.
- Galaxy 2
In Super Mario Galaxy 2, Green Power Stars can be found once the 120 Star ending has been seen, which, as was the case of the first Galaxy game, entails collecting all 120 Stars then defeat Bowser once more in World 6.
Every single Green Power Star is summoned by Green Prankster Comets, which swarm all of the galaxies after the 120 Star ending. These stars are hidden throughout each of the Galaxies, with one Green Power Star for every Star in a galaxy. For example, if there are three normal Power Stars in a galaxy, there will be three Green Stars, making a total of six.
All 120 Green Stars are required to unlock the final galaxy of the game, Grandmaster Galaxy, which is the only galaxy that does not have Green Stars.
Super Mario 3D World
In Super Mario 3D World, Green Stars are the replacement for Star Medals, and by extension, Star Coins. There are 380 Green Stars in all for this installment. How many Green Stars can be found in a course depend on the stage in question:
- Normal & Castle Courses have 3 Green Stars.
- Blockades & Boss Blockades have 1 Star.
- Captain Toad Courses (nearly exclusive to odd numbered Worlds) have 5 Stars.
- Mystery Houses (exclusive to even numbered Worlds) vary, swinging between 5 or 10 Stars, except for the last one in World Crown, which has 30.
Super Smash Bros. for Nintendo 3DS/Wii U
Super Smash Bros. Ultimate
In Super Smash Bros. Ultimate, Rosalina has a green alternate costume appearing to be based of the Green Power Star's color scheme.