Fourth Wall

Breaking the fourth wall is a comedy device used in fictional stories in which a character acknowledges the fact that they are a character in a show or television show, and are actually aware of being such. There are several ways of breaking the fourth wall; examples include when a character refers to a particular part in a television episode, when a character stops others from performing an occult or criminal act by referring to the fact that it is a "children's movie/show," when a character responds to a real world person who is not physically present (such as the narrator), or when a character talks directly to the viewer.

List of instances where the fourth wall is broken
Season 1
 * "The Mystery":
 * Gumball breaks the 4th wall when he says, "I said it was him!" to whoever is shining the light on someone.

Season 2

 * "The Apology":
 * Gumball asks why he has to run every 8 minutes of his life, 8 minutes into the episode.
 * "The Flakers":
 * Anais breaks the fourth wall when she winks at the camera.
 * "The Dream":
 * Gumball and Darwin fight over a censorship panel.
 * "The Game":
 * Gumball pulls a card that says "Dramatic Music Until the End of the Game."
 * "The Voice":
 * Tobias indirectly mentions how he feels like he's the supporting character of his own life.
 * "The Castle":
 * Darwin realizes how Gumball's voice has changed, referencing the change of his voice actor's voice.
 * "The Sweaters":
 * Gumball mentions how the episode will end.
 * "The Finale":
 * Anais noticing that they were relatively unscathed after falling from such a large height in "The Responsible," a reference to the humorous laws of cartoon physics.
 * Richard explaining that when he is placed in prison, he is suddenly "just not in there anymore," a reference to the shift back to the status quo at the end of episodes.
 * Gumball noticing how they looked different in the family album, a reference to the transition in drawing style and animation that occurred between Season 1 and Season 2.
 * Gumball wondering why the episode looked like it would not end happily, a reference to how most episodes end happily.
 * Gumball stating that only a total reality reset could save them, a reference to how the ending of episodes tends to revert the town back to normal, also known as deus ex machina.

Season 3

 * "The Kids":
 * Gumball's face is squished by Patrick's side of the split screen.
 * Gumball states that he's been twelve years old, referencing how cartoon characters don't usually show age development.
 * Darwin states that he and Gumball are the people on TV who don't age.
 * "The Fan":
 * After Sarah tells her joke to Gumball and Darwin, a live audience is heard laughing.
 * After Sarah speaks to the viewer, the animation pauses two times, and the words "The End" and "Executive Producer: Sarah G. Lato" appear on the bottom of the screen.
 * Sarah breaks the fourth wall by singing the show's ending theme.
 * "The Joy":
 * The camera squishes Miss Simian's face. Another instance is when Miss Simian asks for the time, and the time-card crashes into her.
 * In many instances, rainbow liquid splashes onto the camera.
 * "The Puppy":
 * Gumball, Darwin, and Anais speak to the viewer multiple times throughout the episode.
 * "The Extras":
 * The Minor Characters are fully aware of their background status and blame Gumball and Darwin for it. The Green Bear also points directly at the viewer, rather than Gumball and Darwin.
 * "The Fraud":
 * Principal Brown breaks the fourth wall in this episode when he points out that Gumball and Darwin's nudity is pixelated.
 * "The Void":
 * Gumball's face comes closer to the camera.
 * "The Allergy":
 * Darwin sneezes on the camera, causing the screen to crack.
 * "The Procrastinators":
 * Darwin points the laser beam at the camera.
 * "The Saint":
 * Gumball throws grease at the camera.
 * When he tries to mess up Alan's Elmore Plus account, Gumball's comment, "Oh, my gosh! Why are there so many drawn people in Elmore? Go back to your flat country and stop ruining our economy!" is a reference to the 2-D characters in the show. He says to Darwin that "no one likes a 2-Dist."
 * "The Safety":
 * Gumball, Anais, and Nicole crash into a "viewer discretion" notice.
 * Also, Darwin messing with Elmore to keep everyone safe causes a few fourth wall breaks.
 * "The Countdown":
 * Gumball crashing into the screen, freezing time.
 * Gumball and Darwin interact with the on-screen timer, mentioning how it took them a minute to get far out in the desert.
 * The Downer":
 * Gumball speaks and sings to the viewer for most of the episode.
 * The Money":
 * Gumball states that with no money, they're nothing,
 * The 2D characters turn into storyboards while the CGI characters glitch as the animation begins to degrade.
 * The scenes then become a storyboard while the Watterson family are running to the mall. After The Wattersons (except Gumball) sign the Joyful Burger contract, the storyboard then returns to its animation quality.
 * When the family tells Gumball that advertising is not necessarily selling out, Darwin winks and Gumball asks him who he's speaking to, implying that he was talking to the viewer. Anais also spoke directly to the viewer.

Season 4

 * The Return
 * A radio announcer says "And now, three minutes fifty of non-stop chase music!" mainly because Richard is in an intense situation.
 * The Others
 * The fourth wall is broken in different ways when Anais reveals her classmates.
 * The Signature
 * Gumball recognizes suspenseful background music.
 * The Pest
 * Billy makes fun of Gumball's sweater and says "2011 called and said to keep it, as it wasn't cool when you started wearing it," which is a reference to the year of the show's premiere.
 * The Gift
 * Alan talks and tries to stay with the camera, but gets angry when it ignores him.
 * The Routine
 * Mr. Rex breathes on the camera.
 * The Uploads
 * Gumball finds a trailer for The Amazing World of Gumball Movie.
 * The Apprentice
 * The Goblin makes fun of Mr. Fitzgerald by asking "are you in a television show, or at a business?".
 * The Origins
 * The camera crashes into Gumball's face.
 * The Girlfriend
 * Gumball asks Darwin if he notices the suspenseful background music.
 * The Signal
 * The title card glitches up.
 * Interruptions with satellite TV in Elmore turn out to be causing the actual town to glitch and only Gumball seems to be aware of it.
 * Gumball and Darwin come to the conclusion that they're in a TV show, but the episode jumps to Nicole, Anais, and Richard eating dinner.
 * The ending theme plays as the episode glitches one last time.
 * The Advice
 * When Coach hits Banana Joe, they both crash into the camera.
 * The Love
 * The narrator of the chemistry sequence is speaking directly to the viewer.

Trivia

 * Gumball breaks the fourth wall more than any other character.
 * Season 3 has had the most fourth wall breaks than any other season so far.