Prankster Comet

"It seems that a Prankster Comet has appeared somewhere...Prankster Comets have very strange effects on galaxies..."

- Rosalina

Prankster Comets are special missions that appear in Super Mario Galaxy and Super Mario Galaxy 2. They affect galaxies by changing the gameplay of the level.

In Super Mario Galaxy, there are five different types of Prankster Comets, each one a different color: red, white, blue, yellow, or purple. They appear occasionally in the orbits of the 15 major galaxies, starting at the point when Mario or Luigi collects his thirteenth Power Star. The missions can be done only if the player travels to a galaxy with a Prankster Comet in orbit. Prankster Comets appear in galaxies only after a specific Power Star in any given galaxy is collected. Also, when a Prankster Comet is in orbit, the player is forced to choose its level. No option is given to choose "normal" levels. However, Comet Tico, who is positioned near the Terrace, can shuffle the comets between available galaxies if fed 20 Star Bits by the player. Its actions either remove all comets from orbiting in galaxies, remove some of them, or make some appear.

By completing the event, the player receives a Power Star. While a Prankster Comet is in orbit of a galaxy, players need to completely restart the level each time they lose a life, instead of coming back at the last checkpoint. Once a Prankster Comet's Star has been collected, its Star becomes a selectable mission, only causing the comet to return to the corresponding galaxy at the player's request. All the Prankster Comets (except Purple Comets without time limits) also have their own music that plays during their missions.

In Super Mario Galaxy 2, Prankster Comets appear only once the player has collected a Comet Medal in a certain galaxy, as well as a certain number of those from other galaxies (and collected at least four Power Stars from World 3). In this game, Prankster Comets with different effects are no longer considered different types of comets. Galaxies under the influence of a Prankster Comet are given a generic symbol. Below, the Super Mario Galaxy 2 comets are grouped together based on the title of the mission they appear in. Comets are now yellow if they give Power Stars, while comets are green if they give Green Stars. Traveling to a galaxy with a comet in orbit opens up the comet Star mission, although the player may have the option to select a normal mission, unlike in the first game. Also, a Prankster Comet is always in orbit around a galaxy once unlocked, unlike in the first game, where completing a mission can move the Prankster Comet to another galaxy. Certain galaxies such as the Fluffy Bluff Galaxy and Boo Moon Galaxy do not have Prankster Comets.

Speedy Comet
A Speedy Comet  requires the player to complete a level within a certain time limit, from four to six minutes; failing to do so results in the player losing a life. Also, there are small changes in the galaxies. For example, the Good Egg Galaxy's Ruby Rocks are all replaced by Chomps. Four galaxies are visited by Speedy Comets: the Good Egg Galaxy, Space Junk Galaxy, Dusty Dune Galaxy, and Dreadnought Galaxy.

Speedy Comets also appear in Super Mario Galaxy 2. A list of galaxies visited by it includes the Sky Station Galaxy, Bowser Jr.'s Fiery Flotilla, Hightail Falls Galaxy, Bowser's Lava Lair, Rolling Masterpiece Galaxy, Supermassive Galaxy, Bowser's Gravity Gauntlet, Throwback Galaxy, Bowser's Galaxy Generator, the Stone Cyclone Galaxy, and the Boss Blitz Galaxy. Unlike in the previous game, a Speedy Comet in Super Mario Galaxy 2 can dramatically change the original level in addition to setting a time limit. For example, Hightail Falls Speed Run has damaged platforms and meteors, and Masterpiece Speed Run has an entirely new planet not seen in the original Star mission as part of the level. Unlike in the first game, the timer disappears once the Power Star appears.

Galaxies marked with "+" next to their time limits have clocks scattered throughout the missions; collecting one adds 10 seconds to the player's time limit.

Daredevil Comet
A Daredevil Comet cuts Mario or Luigi's maximum health down to only one hit point, as opposed to the usual three (or six with a Life Mushroom). Additionally, it removes all Life Mushrooms and coins from the level so that the player cannot gain more health or exploit a glitch to take damage without losing a life, and coins do not spawn from stomping enemies. Five galaxies are visited by Daredevil Comets: Battlerock Galaxy, Ghostly Galaxy, Gusty Garden Galaxy, Deep Dark Galaxy, and Melty Molten Galaxy. The former four have the player battle a previously fought boss (Topmaniac, Bouldergeist, Major Burrows, and Kamella, respectively), while Melty Molten Galaxy has the player complete the entire first mission (The Sinking Lava Spire) with only one hit point. Taking any damage during a Daredevil Comet requires the player to start the mission over from the beginning. At the start of the first four aforementioned galaxies, the player is automatically brought to the last planet where the boss resides, without the need to travel throughout the galaxy.

Daredevil Comets are also in Super Mario Galaxy 2 in Spin-Dig Galaxy, Bowser Jr.'s Fearsome Fleet, the Slipsand Galaxy, Bowser Jr.'s Boom Bunker, the Battle Belt Galaxy, and the Grandmaster Galaxy. Unlike in the original Galaxy, however, some of the daredevil runs in Super Mario Galaxy 2 have Checkpoint Flags. Just like with a Speedy Comet, the original level can be dramatically changed when visited by a Daredevil Comet. For instance, one planet is replaced by another one in Bowser Jr.'s Boom Bunker.

Cosmic Comet
A Cosmic Comet  pits Mario in a race against Cosmic Mario in a predetermined course with a Power Star at the end. Mario must beat his duplicate to the Star; if he fails, he loses a life. Four galaxies are visited by Cosmic Comets: the Honeyhive Galaxy, Freezeflame Galaxy, Gold Leaf Galaxy, and Sea Slide Galaxy. If the player uses Luigi, they race against Cosmic Luigi instead. Unlike Cosmic Mario, Cosmic Luigi long-jumps frequently and takes advantage of some shortcuts that are available. Cosmic Comets appear only in Super Mario Galaxy; they are replaced by Clone Comets in Super Mario Galaxy 2.

Fast-Foe Comet
A Fast-Foe Comet speeds up all enemies and obstacles in a stage. Mario must complete the stage while avoiding the accelerated enemies and obstacles. Only two galaxies are visited by Fast-Foe Comets: the Beach Bowl Galaxy and Toy Time Galaxy. Tox Boxes, Thwomps, and moving platforms are the only objects affected. Fast-Foe Comets appear only in Super Mario Galaxy; they are replaced by Double Time Comets in Super Mario Galaxy 2.

Purple Comet
A Purple Comet is available only after the player clears Bowser's Galaxy Reactor. Purple Coins are hidden throughout the galaxy, and Mario must retrieve at least 100 Purple Coins, sometimes within a time limit, to retrieve the Star. Some Purple Comet missions have more than 100 Purple Coins, but Mario still needs to collect only 100 for the Star. All 15 major galaxies are visited by Purple Comets. Timed Purple Comet missions, as well as the Battlerock Galaxy's and Dreadnought Galaxy's Purple Comet missions, use a unique background music track, which is a remix of the Gusty Garden Galaxy music.

The total number of Purple Coins available in a mission is 100 plus the number listed in the "Extra Purple Coins available" column.

There are also Purple Comets in Super Mario Galaxy 2. They are the same as in Super Mario Galaxy, but instead of having to beat the game for Purple Comets to come, only the galaxy's Comet Medal is required. The mission in Starshine Beach Galaxy plays the Hightail Falls Galaxy music, since the Dash Pepper is needed to clear, even though the normal level has a Dash Pepper and using it does not change the music. The specific Purple Coin theme from the first game plays in the Flip-Swap Galaxy, Puzzle Plank Galaxy, Clockwork Ruins Galaxy, and Mario Squared Galaxy. Unlike in the first game, during the Purple Coin missions with time limits, the timer disappears once the required number of Purple Coins is collected.

Clone Comet
A Clone Comet  replaces the Cosmic Comet from the first game. Multiple Cosmic Clones appear in a selected mission. The player needs to redo the whole or part of the mission while there are Cosmic Clones. Clone Comets appear in the Cloudy Court Galaxy, the Haunty Halls Galaxy, the Chompworks Galaxy, and the Flip-Out Galaxy. The comets are fused with the missions Purple Coin Shadow Vault for Puzzle Plank Galaxy, Luigi's Purple Coin Chaos for Mario Squared Galaxy, and Green Star 2 for Flip-Out Galaxy. The specific music for the Cosmic Clones theme does not play (except in the Cloudy Court Galaxy), even though the soundtrack stays the same. This music is also played in other stages such as Stone Cyclone Galaxy. Clone Comets appear only in Super Mario Galaxy 2.

Romp Comet
A Romp Comet  requires Mario to defeat a horde of 30 enemies within a time limit by using a power-up, with the exception of the Flash Black Galaxy, where no power-up is given. Romp Comets appear in the Yoshi Star Galaxy, the Boulder Bowl Galaxy, the Flash Black Galaxy, and the Shiverburn Galaxy. The comets appear only in Super Mario Galaxy 2.

Double Time Comet
A Double Time Comet  makes the player redo a level, this time with the hazards moving faster. Double Time Comets appear in Beat Block Galaxy and Twisty Trials Galaxy. These comets are similar to the Fast-Foe Comets from the first game, except that instead of enemies, the stage hazards move faster, and slightly slower overall than when a Fast-Foe Comet is in orbit. Despite the comet being called the "Double Time Comet," the objects actually move at four times the normal speed. Double Time Comets appear only in Super Mario Galaxy 2.

Green Comet
A Green Comet  makes Green Stars appear in various levels in every galaxy except the Grandmaster Galaxy, usually in hidden or hard-to-reach places. There is one Green Star for every normal Power Star mission; galaxies with two missions have two Green Stars to find, and galaxies with three missions have three Green Stars to locate. In either case, Green Star levels are always named "Green Star 1" and "Green Star 2" (as well as "Green Star 3" for galaxies with six Power Stars total) as opposed to being named the same way as normal galaxy levels. Green Comets appear only in Super Mario Galaxy 2.

Trivia

 * When a Prankster Comet level is selected, a vignette covers the corners of the screen. In Super Mario Galaxy, the color of the border matches the comet's color. In Super Mario Galaxy 2, the vignette is always black (the same as the Daredevil Comet effect in Super Mario Galaxy).
 * For Green Comets, there is no vignette at all, presumably to give the players more vision. Instead, the black border during the mission intro and the black fade-out circle after getting a star or losing a life become green.
 * In Super Mario Galaxy 2, Mario and Luigi do not fall asleep while idle when a Daredevil Comet is active, with the exception of The Perfect Run.
 * The Speedy/Daredevil Comet music also plays toward the end of the missions Sunbaked Sand Castle in the Dusty Dune Galaxy and The Sinking Lava Spire in the Melty Molten Galaxy.