Castle world

'Castle world' (As referred to game designer Gregg Mayles on Twitter ) is the beta version of Cauldron Keep. This castle world has no official name, however, it was a more extensive area than Cauldron Keep with Jiggies, Mumbo Pads and a Jamjars. It was eventually turned into Cauldron Keep after "time ran out" with some original assets being re-used. The addition of this world to the 9 already in the game (including Isle o' Hags) would've lead to a total of 100 Jiggies in Banjo-Tooie, matching the amount in it's predecessor, Banjo-Kazooie. However, assuming 100 Notes would also exist in this level, the addition of this level would bring the total Note count in Banjo-Tooie to 1,000; beating Banjo-Kazooie by 100 Notes.

This world would be linked to Cloud Cuckooland via a beanstalk on the upper floor. There is a Mumbo Pad near by, and the beanstalk would be created via planting a seed and presumably using the Mumbo Pad to grow it, making it seem like this world's Mumbo Pads would be to do with heat. This is further suggested as another Mumbo Pad is also near a Raven's Egg, suggesting that Mumbo would use the heat power to hatch the egg. As well as this, the other assumed use of the Mumbo Pad in this level is to switch off a power box to de-electrify a floor. Mumbo's Skull would be to the right hand side of the castle as Banjo entered the level. Mumbo would enter the level via stepping stones before the drawbridge is open, making it seem like Mumbo would have to enter the castle to make Banjo and Kazooie able to enter it at a later point. This implies that a Glowbo is on the Castle exterior.

Warp Pads would be covered with a 'bubble' over it, in which the 'bubble' would disappear with the press of a nearby switch. In addition to this, there would be indicator lights on the base of the pad letting Banjo know whether it was usable or not (Red disignating that it was unsuable, Green stating it would be usable), this colour change would show whether it has been powered from the Teleport Power Room.

Certain things were maintained between the 2 iterations of 'Castle World'. These include the laser grid entrance and the additional Jiggy barrier to the top of the castle with an additional puzzle challenge.

Due to the quality of the images posted on Twitter by Gregg Mayles, some notes on the pages are hard to deduce, especially on the image showing the castle exterior.

Jiggies

 * 1) Laser Grid: There is a circular room called the 'Treasure Chamber' (Not to be confused with the Treasure Chamber in Mayahem Temple) where there are lasers criss-crossing along the floor. On one area of the room, there is a podium with a Jiggy on it. Either Banjo, Kazooie or the pair of them would enter this room directly from the outside (in the same position as what would become The Gatehouse). It is presumed that either Kazooie's Glide maneuvre or just using Flap Flip would be needed to traverse the grid without taking damage to reach the Jiggy. Banjo on his own can also view this room with the use of Shack Pack. However, he cannot perform the puzzle via this method as his access to the main room is cut off by viewing glass.
 * 2) Top of the Castle: There is a jiggy in the cone above the central pillar on top of the castle. The cone is glass at the tip of the cone which can be shattered. Whether the shattering would be caused by a Beak Bomb or a switch is unknown.
 * 3) Glide to the Alcove: On top half of the 'Glide Tower' is a Kazooie Switch which must be pressed to open up a door covering an alcove lower in the Glide Tower. This would then presumably keep the door open even if Kazooie were to step off the Kazooie Switch. If this is the case, Kazooie could fly down using her glide maneuvre to reach the Jiggy.
 * 4) Not mentioned
 * 5) Not mentioned
 * 6) Not mentioned
 * 7) Not mentioned
 * 8) Not mentioned
 * 9) Not mentioned
 * 10) Not mentioned

Jamjars

 * The Armoury

Jinjos

 * None Shown (none implied due to the 9 houses already filled)

Extra Honeycombs

 * None Shown

Cheato Pages

 * None Shown

Glowbos

 * Presumed Exterior

Others

 * Treble Clef Assumed to have been included. Unknown location if it has been included.

Moves Learned

 * There is a move learnt by Jamjars in the Armoury, but there is no indication what this move might be. It might be a previously learnt move which would be transferred to this level rather than being in a previous level.

Areas

 * Castle Exterior
 * Glide Tower
 * Treasure Chamber (Not to be confused with the Treasure Chamber in Mayahem Temple)
 * Rooftops
 * Dark Tower
 * Firing Range Room
 * Electric Floor Room
 * Armoury
 * Teleport Power Room
 * Graveyard

Trivia

 * There are at least 18 pages of drawings for this level, but only 5 are shown in the tweet (#1, #7, #10, #11 and #18)
 * Drawings seem to have been dated in an unusual order. First #11 on the 4th Nov 1999, then #10 on the 5th, then #7 and #18 on the 8th and finally #1 on the 9th