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Rare Orbs, referred to as Orbs in the Prima guide, are important collectible items that appear in Donkey Kong Country Returns and Donkey Kong Country Returns 3D. They are held in the secret temple of each of the first eight worlds. The temples have to be unlocked by collecting the hidden K-O-N-G Letters in each of the other levels.
In order to get the Rare Orb, the Kongs must get past all of the obstacles and enemies in the temple. Once all eight orbs are collected, they will be able to unlock the entrance to the hidden Golden Temple.
In New Mode on the 3DS version, after the game is beaten, each of the Rare Orbs are found in Cranky Kong's Shop (one per world) and can be purchased after spending 50 Banana Coins instead of doing the temple levels. This totals up to a price of 400 Banana Coins for buying all 8 Rare Orbs.