Curious Rainbow Mine

The Curious Rainbow Mine is a recurring event in Cookie Run: OvenBreak. This event is split into two areas, the Rainbow Cube Depot and the Rainbow Cube Mine. The Depot is full of many Rainbow Cubes to collect, and all players can run in it. The Mine can only be entered by players who earned a Puzzle Key from the previous Grand Champions League, and they can collect Rainbow Gems here to level up the Depot and increase the amount of cubes everyone can earn. The Curious Rainbow Mine was introduced on May 7, 2019, and has reappeared after every Grand Champions League.

Rainbow Cube Depot
The Rainbow Cube Depot, also called the Rainbow Depot, is the area available to everyone. This is a short, simple course with no Jellies or Coins to collect and no pits or obstacles to avoid. Energy is not a factor and no score is recorded, the only goal is to collect the Rainbow Cubes on the path. Big Rainbow Cubes exclusively appear here, each worth ten Rainbow Cubes. This stage must be played with a fixed Combi, using the Cookie that the previous Champions League Big Season was themed after, accompanied by their Pet. Angel Cookie's passive Magnetic Aura was permitted, but all other bonuses, including Magic Candy, Cookie and Pet levels, Affection, Escape Level, and Treasures have no effect. The Depot starts with a small number of Rainbow Cubes, but as Key holding players collect Rainbow Gems, the Rainbow Depot will level up and let everyone collect more Rainbow Cubes, up to 225 per run at the maximum level 5. All players can run in the Depot once daily. When the depot is upgraded after a player has already run that day, they can run again.

Rainbow Cube Mine
The Rainbow Cube Mine, also called the Rainbow Mine, is the special area available only to players with a Puzzle Key. The contrast between the Depot and Mine could not be greater, as it is a very long and difficult area. Here, the objective is to collect Rainbow Gems to help level up the Depot. There are 70 Rainbow Gems in the Rainbow Mine at fixed locations. These are spread out throughout five floors, starting from B1. The highest amount of Gems collected in a single run is the amount contributed.

The first three floors each have three stages followed by a random stage with no Rainbow Gems. Floor four has four stages before its random stage, and floor five has five fixed stages followed by the Bottomless Mine. Each normal stage begins with Pink Bear Jellies arranged into numbers corresponding to the floor and stage. Random stages start with Pink Bear Jellies arranged to spell out "Random" and a number made of Yellow Bear Jellies. Each normal stage ends with some small arrows made of silver Coins, and random stages before the Bottomless Mine end with Pink Bear Jellies spelling out "Go Go Go" above Giant Star Jellies. The Bottomless Mine has incredibly hard random stages. These start with Pink Bear Jellies writing out "Hard Random", and each one ends with a Rainbow Gem in an easy to grab place, until all 70 have appeared.

Like in the Depot, the featured Cookie and Pet are fixed. Angel Cookie's Magnetic Aura and Choco Drop and Celestial Star's abilities functioned in the Mine. Unlike the Rainbow Cube Depot, Treasures can be used here, but all other bonuses are unavailable. Rainbow Gems are immune to magnetic effects, and score is not a focus, so many Treasures have limited use. Defensive Treasures like the Shield Bubble Gun, Divine Guardian Shield, and X-tra Hot Turbo Engine are recommended, as well as positioning Treasures like the Bubble Gum Spring Jumpers and Carrot Pudding Trampoline.

Key holders can complete missions in the Rainbow Cube Mine when the depot is leveled up and for collecting the required Rainbow Gems. Due to the difficulty, there are only missions up to 55 Rainbow Gems. When the event ends, key holders are also rewarded Crystals and Spirit Potions based on their Contribution Rank. This rank is based on Rainbow Gems collected in a single run. Score is only used to break ties when multiple key holders collect the same amount of Gems.

Puzzle Key
A Puzzle Key is needed to enter the Rainbow Cube Mine. It is earned from advancing far enough in the Grand Champions League. In the first Grand Champions League, champions had to reach round four to obtain one. In all later Grand Champions Leagues, champions only need to reach round two. All players who earned a Puzzle Key in the previous Grand Champions League have unlimited access to the Rainbow Cube Mine during the event.

Updates

 * February 13, 2019
 * Puzzle Key given to champions who reached Round 4, though its purpose was not revealed.
 * May 7, 2019
 * Curious Rainbow Mine opened.
 * GingerBrave and Choco Drop featured.
 * February 7, 2019
 * Puzzle Key given to champions who reached Round 2.
 * September 19, 2019
 * Curious Rainbow Mine re-opened.
 * Angel Cookie and Celestial Star featured.
 * Records are now based on Rainbow Gems collected in a single run.
 * More Rainbow Gems required to level up the Mine.
 * February 6, 2020
 * Puzzle Key given to champions who reached Round 2.
 * March 12, 2020
 * Curious Rainbow Mine re-opened.
 * Devil Cookie and Flame Bat featured.
 * June 13, 2020
 * Puzzle Key given to champions who reached Round 1.
 * August 7, 2020
 * Curious Rainbow Mine re-opened.
 * Ninja Cookie and Little Ghost featured.

Trivia

 * The Secret Crystal Cave event was a precursor to the Curious Rainbow Mine.
 * This event was negatively received by many players, particularly when it was first introduced. Players who did not earn a Puzzle Key criticized the Rainbow Mine being available to a small percentage of players and the Grand Champions League prerequisite, while players who earned a Puzzle Key criticized the tedium involved in running in the Curious Rainbow Mine as well as the value of rewards in relation to the difficulty.
 * After the second Grand Champions League, a bug caused the Puzzle Key to be visible in the inventory of many players who did not receive it, and not visible to some who were meant to have it. This was not fixed in time for the Curious Rainbow Mine re-opening, though the bug was limited to the inventory and did not effect who could enter.