
The Banjo-Kazooie series features Stop ‘n’ Swop, an ambitious cross-game connectivity system involving six differently colored Mystery Eggs and an Ice Key that unlock various rewards across multiple titles. Originally designed as a method to transfer data between cartridges, the feature would have allowed players to collect these unique items in Banjo-Kazooie and transfer them to subsequent games by swapping cartridges within a ten-second window while the Nintendo 64’s Rambus-DRAM retained the data. However, Nintendo intervened in October 1999, ordering Rare to remove the feature due to concerns about potential hardware damage from latch-up conditions and the possibility that future console revisions would reduce the transfer window from ten seconds to one second, making the hot-swapping method impractical and effectively cancelling the original implementation. Despite this setback, Rare incorporated partial Stop ‘n’ Swop functionality into the Banjo-Tooie game, where three Mystery Eggs and the Ice Key could be found as collectible items. The Xbox Live Arcade versions of both titles, released in 2008-2009, implemented Stop ‘n’ Swop as originally envisioned, restoring the cross-game functionality and providing rewards for Xbox 360 users including Dashboard themes and Gamerpics. To access this feature in the original Banjo-Kazooie game, players must complete the 100% ending by collecting all 100 Jiggies, after which Mumbo will show three animated photographs revealing the locations of two Mystery Eggs and the Ice Key in inaccessible places. Players can then unlock these locations by entering specific phrases in the Sandcastle found within Treasure Trove Cove, with each phrase preceded by the word “CHEAT” spelled out using the Beak Buster technique on letter tiles covering the floor. The Sandcastle must first be drained by firing two eggs into Leaky, the bucket that guards it, which will patch him up and cause him to drain the water from the castle. Entering the phrase correctly triggers access to previously inaccessible places containing Stop ‘n’ Swop collectibles, and if players make a mistake while typing, they must restart with the complete phrase from the beginning. Once collected, these items appear in a new menu called Stop ‘n’ Swop accessible after Click Clock Wood in the View Totals section, and they become permanently stored on the cartridge without the ability to remove them through normal gameplay methods.
» Stop 'n' Swop in Banjo-Tooie
In Banjo-Tooie, the Stop ‘n’ Swop system centers around Heggy’s egg-hatching services located in Wooded Hollow, where mysterious eggs discovered throughout the game can be brought for hatching in exchange for special techniques and transformations. Players can locate up to three mysterious eggs total, with the Yellow Mystery Egg pre-positioned within Heggy’s Egg Shed and the Pink and Blue Mystery Eggs hidden behind challenging obstacles that require advanced traversal techniques to reach. The Pink Mystery Egg appears behind a grate in Spiral Mountain that must be broken with a Grenade Egg thrown from above, while the Blue Mystery Egg is found behind a fence at the top of the Spiral Mountain waterfall. To access the Blue Mystery Egg, players must backflip against the wall to catch a ledge and shuffle behind the waterfall. These mysterious eggs must be obtained by defeating Banjo-Kazooie Game Pak enemies found within their respective alcoves, which wobble around and are easily destroyed. When players bring eggs to Heggy’s Egg Shed, she will hatch them to unlock special rewards. The Pink Mystery Egg unlocks the Breegull Bash ability, while the Blue Mystery Egg unlocks the Homing Eggs cheat that can be activated in Mayahem Temple’s code chamber. The Yellow Mystery Egg provides access to Jinjo as a character in multiplayer Squackmatch mode, but requires Kazooie herself to hatch it using the Hatch ability after using Bill Drill on a cracked panel to reveal Split-up pads. The Ice Key can be found in a specially concealed cave in Jinjo Village accessible using the Grip Grab ability, and serves as the primary tool for accessing the frozen vault in Hailfire Peaks’ Icy Side region through Glitter Gulch Mine’s underwater tunnel network. Opening the vault reveals the Mega Glowbo that enables Humba in Pine Grove to transform Kazooie into a green fire-breathing dragon. The Xbox 360 version expands this system through automatic cross-game transfer and introduces exclusive Stop ‘n’ Swop II items including Bronze, Silver, and Gold Mystery Eggs alongside additional rewards such as gamerpics, dashboard themes, and access to the Stop ‘n’ Swop II submenu.
» Stop 'n' Swop in Banjo-Kazooie Nuts & Bolts
In Banjo-Kazooie Nuts & Bolts, the feature requires ownership of the Xbox Live Arcade version of Banjo-Kazooie and the collection of all corresponding items within that game to unlock exclusive vehicle parts. New crates appear at specific locations throughout Showdown Town marked with painted drawings of Stop ‘n’ Swop silhouettes on walls, rooftops and ground surfaces. Each of them is color-coded and positioned based on which collectible players have collected in the predecessor game. Players must transport these crates to Mumbo’s Motors where Mumbo uses his magic to unlock them, revealing unique vehicle parts that cannot be obtained through any other means. The unlocked parts include the Beacon part from the Green Mystery Egg, Goldfish part from the Blue Mystery Egg, Mole-On-A-Pole part from the Cyan Mystery Egg, Googly Eyes part from the Yellow Mystery Egg, Fluffy Dice part from the Pink Mystery Egg, British Flag parts from the Ice Key and Disco Ball part from the Red Mystery Egg. All of these parts function as decorative elements for visual customization, with the Mole-On-A-Pole part being a decorative element resembling Mrs. Bottles’ head stuck to the end of a pole rather than serving any gameplay function. Opening the first Stop ‘n’ Swop crate unlocks a zero-point achievement titled Stop ‘n’ Swop and players who own the L.O.G.’s Lost Challenges downloadable content can unlock seven additional vehicle blueprints by completing Stop ‘n’ Swop in Banjo-Tooie. The game also includes numerous references to the Stop ‘n’ Swop feature throughout its worlds, with Bottles offering to reveal the secret for an impossible 6000 Musical Notes, Trophy Thomas accusing the protagonists of cheating during Jiggy-Challenges, fake Stop ‘n’ Swop eggs in Banjoland containing Gruntbots and an imprint of the Ice Key appearing on top of Boggy’s Gym as environmental decoration.