Fourth wall

The fourth wall is a concept in video games. It refers to the division between the in-game characters and the player. Breaking this division is referred to as "breaking the fourth wall." This is often done with characters explaining controls to the player, or if the characters actively are aware they are part of a game, such would be that the fourth wall is not only broken, but destroyed to a point of no repair.

In the Banjo-Kazooie Universe, it appears that most (if not all) characters are aware they are part of a game, and therefore break the fourth wall constantly. The most extreme example of this is the presence of L.O.G., who appears as the creator of all games, including the one all the characters are currently in.

Banjo-Kazooie

 * "That's it, I'm erasing your memory pack!"-Bottles, after being repeatedly called in Spiral Mountain if you ignore the tutorial.
 * Bottles teaching you new moves and saying the buttons required. (i.e. press B or press Z)
 * "No way. Me and Banjo were the stars of this game."-Kazooie during the BBQ cutscene after the credits.
 * If the player collects all the Jiggies, then Mumbo, Banjo, and Kazooie will talk about Banjo-Tooie. Even getting to see some secrets in that game.
 * "Stupid bear and dumb Kazooie, I'll be back in Banjo-Tooie!"-Gruntilda at the end of Banjo-Kazooie.

Banjo-Tooie

 * "Watch it, this is a family game!" "Oh, so it is." - Banjo and Chief Bloatazin
 * "It's nice to know not every character in this game is bad." - Scrotty
 * "One more press o' that button an' I'll run ye through!" - Captain Blackeye
 * Jamjars teaching moves, similar to Bottles, which he now broke more because of using the button icons.
 * "Pressing the joystick only slightly will make you tiptoe silently" - Sign post in Mayahem Temple. (Breaks wall because signs say things like "ever check here?")
 * "There are no more tickets. They all sold out while you were playing Banjo-Kazooie!"-Unogopaz Chief Unogopaz
 * "Thank goodness, Kazooie won't want to see another egg for the rest of the game."-Banjo after returning Terry's last child.
 * "Bottles taught us loads in the last game." Kazooie
 * "He wasn't the favorite character in Banjo-Kazooie..." Kazooie, upon Bottles' death.
 * "I was the star of the last game..." Bottles' Ghost
 * "Huh, looks like this room is empty." "It can't be, the musics changed."-Banjo and Kazooie, upon entering one of the rooms where you fight Klungo.

Banjo-Kazooie: Grunty's Revenge

 * Bottles' teaching, yet again.

Banjo-Kazooie: Nuts & Bolts

 * Before a battle between Banjo and Gruntilda commences, the screen "pauses" and the word "PAUSED" appears on the screen.
 * L.O.G. mentions that everything in the Banjo-Kazooie world is a video game countless of times.
 * "I would like to keep you like this, but I believe the people would like to take part in this game" - L.O.G.
 * "My fear is the people will not be able to form real words." Kazooie

External link
For more information, see fourth wall on Wikipedia.