Banjo-Kazooie is comprised of several non-linear 3D worlds in which the player must gather jigsaw pieces, or "Jiggys", to progress. Banjo and Kazooie are aided by Bottles, who teaches them new abilities, and Mumbo, who uses magical powers to transform them into other creatures, such as a termite or crocodile.
The player progresses in the game by finding Jiggys, Musical Notes and Mumbo Tokens. Jiggys open doors to new worlds by collecting enough to complete the corresponding jigsaw puzzle. There are ten in each world; nine must be found, and one is granted by finding all five Jinjos on each world. Musical Notes open note doors that allow Banjo and Kazooie to progress further into Gruntilda's lair. There are 100 notes in each world, and 900 total in the game. Mumbo Tokens grant the player magical transformations at Mumbo's hut when the player collects a sufficient amount.
Besides these primary items, the player can also collect items which are used in performing certain moves. Bottles must teach Banjo and Kazooie the move before the item can be used. Items include blue eggs, red feathers and gold feathers, which can be held in quantities of up to 100, 50 and 10, respectively. Blue eggs are fired as projectiles or ejected from Kazooie's rear, and bounce slowly until they either hit an enemy, or break on their own; red feathers are used in flight and flying attacks; and gold feathers are for the most powerful attack, Wonderwing, which uses Kazooie's wings to make her and Banjo invincible and can kill almost any enemy, or at least protect the bear and bird. Rarer, temporary items can be found which have specialized use in puzzle-solving, namely wading boots, which enable the crossing of hazardous terrain, and turbo trainers, which grant extra running speed, often as part of a race or a time-based puzzle. Other items include extra lives and honeycomb energy, which respectively increase the player's lives and health, and extra honeycomb pieces, which give the player a permanent increase of one honeycomb of health for every six collected.