Super Monkey Ball 3: Banana Crazy (lost build of cancelled GameCube sequel platformer; 2002-2004)
Super Monkey Ball is a series of arcade-style platform video games published by Sega, commencing in June 2001 with the release of Monkey Ball in arcades and subsequently an enhanced GameCube port entitled Super Monkey Ball later in the same year. The franchise follows Aiai and his monkey gang, who are controlled by the player in a gachapon ball they use to navigate each level from tilting the world itself, instead of the characters. Throughout it's history spanning over two decades, the series’ first two games remain the most notable and beloved, in sharp comparison to most of the titles following Super Monkey Ball 2 in 2002. Prior to leaving the Gamecube and going multi-platform, an intended third Monkey Ball for the Nintendo GameCube was being considered, but was quietly cancelled before it ever saw a release.
The first public mention of Banana Crazy originated from an IGN article in May 2003, from reports that Japan magazines were mentioning that the game would release in early 2004. Allegedly, the title would have featured the same foundation found in the previous installments, but introduce LAN support, with one mentioned perk being having eight players join at the same time in multiplayer mode across multiple interconnected television sets. The article had also mentioned the possibility of Banana Crazy at E3 2003, but no mention of the project from Sega appeared. Additionally, reports from Neogaf members who attended the event suggested that the game was not being developed from encounters they had with representatives of Sega and series creator Toshihiro Nagoshi, though whether or not this was a misdirect to keep the game hidden until a proper announcement is unclear.
In IGN's January 2004 article discussing the list of upcoming 2004 GameCube games, it was mentioned once again, albeit with the same information from their original write-up. In their final reference to Banana Crazy from a June publication in the same year while discussing the unearthed listing for Super Monkey Ball Deluxe, the game was said to still be in progress of being released, though no new information was given as it's proposed 2004 release was looking more unlikely following no appearance at E3 2004. 
Three years later, while being interviewed for the then-upcoming Super Monkey Ball: Banana Blitz in April 2006 with IGN, Nagoshi was asked about if there was a third Monkey Ball being developed prior to the Nintendo Wii title. He had replied with:
"It's just a rumor. I wonder when "a long time ago" is."
However, contrary to Nagoshi, a trademark of the third game, underneath the reported title of Banana Crazy, was filed from Amusement Vision, the developers of the first two games, in June 2002, before being publicized in July 2003 and granted in October 2004, suggesting the game was in production after all.  The trademark's document also had a description of what the finalized logo would’ve been like on the penultimate page:
The word "SUPER" and the border around BANANA CRAZY are red. The spheres with "SUPER" on them and the words "BANANA CRAZY" are blue. The words "MONKEY BALL" and the design of a bunch of bananas are yellow. The spheres with "MONKEY BALL" on them are red with green and blue bands.
The trademark later expired in January 2005, which was around the same period of Sega’s restructuring phase with all of it's divisions, Amusement Vision included. Furthermore, earlier in February 2004, a Eurogamer article mentioned that Amazon UK had displayed a listing of Super Monkey Ball 3, while discussing an appearance by Nagoshi on a perplexing column in a Nintendo Dream magazine issue dropping the word of “kanshi” while being asked what was next for the franchise, which translates to the Japanese term of the Chinese zodiac, and with by chance, the Year of the Monkey also being in 2004, encouraging the idea that Banana Crazy was at some stage of being realized.
Aside from the trademark being known to exist, no other material, including any possible gameplay sinepts or concept art, of Banana Crazy has surfaced as of February 2022. It’s also subsequently left ambiguous how much development was produced before the game's cancellation, though it has been speculated elements of the game became part of Super Monkey Ball Deluxe in 2005 for the Playstation 2 and Xbox.
- Super Monkey Ball Mini (found promotional tie-in Flash game of GameCube platformer; 2001)
- Super Monkey Ball 2 (partially lost promotional monthly wallpapers for GameCube sequel platformer; 2002)
- IGN's page on Banana Crazy.
- Super Monkey Ball Wiki's page on the subject.
- The Banana Crazy trademark document.
- IGN's first report of Banana Crazy. Retrieved 12 Feb '22
- A Neogaf discussion thread of Banana Crazy in June 2004. Retrieved 12 Feb '22
- IGN's second mention of the game in a report discussing the lineup of 2004 GameCube games. Retrieved 12 Feb '22
- IGN's final allusion to the game in June 2004. Retrieved 12 Feb '22
- Nagoshi being asked about Banana Crazy in an IGN interview. Retrieved 12 Feb '22
- Status of the Banana Crazy trademark. Retrieved 12 Feb '22
- Description of the Banana Crazy logo. Retrieved 12 Feb '22
- History of the trademark's document descriptions. Retrieved 12 Feb '22
- Report of Banana Crazy on UK Amazon and Nagoshi's Nintendo Dream appearance. Retrieved 12 Feb '22