List of unreleased media

Due to various reasons (ranging from being of poor quality, developing a game for a failed or soon-to-be-discontinued system, or the company facing financial or legal woes), a project can end up being canceled and cease production. Despite their status, concepts present in canceled games and other media can be reused in commercial releases, and some canceled games are repurposed into different projects.

A game in development can also end up becoming , a term for projects that are announced and for which development is started, but for similar reasons, were never published.

The following is a list of Mario media that has been canceled, or was never produced or released.

Low-information games and rejected pitches
This section lists rejected pitches (meaning ideas proposed internally or to Nintendo without seriously going into production) and canceled projects that have too little information to warrant their own page.

Archie Comics Mario comic pitch
Comic book publisher (which has published other comics based on famous video game properties including ' and ') pitched a Super Mario comic book series to Nintendo, but it was rejected. , as confirmed by writer. The concept art for the pitch was drawn by Archie artists and Ben Bates.

Boss Game Studios' Mario game pitch
Sometime during the late 90's, pitched a Mario game to Nintendo of America. The only know proof of its existence is a storyboard, drawn by Patrick Michael Clark, bought in an online auction showing Mario stepping on a wooden plank, following by the wooden plank sprouting legs and walking in Mario's direction. According to a Boss Game Studios employee, "The Mario thing I think was for a proposal. I’m not sure if we were trying to get the license from Nintendo to produce a Mario game, or if they approached us to do one. Either way, I think it died on the vine after they saw the concept art"

CD-I Donkey Kong game
A Donkey Kong game was in development for the Philips CD-i. The only known report of it is the LinkedIn resume of programmer Adrian Jackson-Jones, which states the game was in development during the 1992-1993 period at RSP. Jackson-Jones "designed and implemented the game engine" for the project.

Donkey Kong Country 4
According to Rare employee Paul Rahme, it was internally suggested at Rare to make a new Donkey Kong Country game for the Nintendo DS, as remaking the trilogy for the Game Boy Advance gave the developers experience and a good basis for making a sequel. The pitch ended up not getting much traction internally and was dropped.

Donkey Kong parking attendant arcade game
In 1983, before creating the game show  and producing Hotel Mario, entertainment producer Steve Radosh was involved in developing an arcade game starring Donkey Kong as a parking attendant for Sega, as the company had rights to the property at the time. The game was canceled when, the American conglomerate which at the time was ' corporate parent, sold its ownership of Sega's U.S. assets to pinball machine maker.

Mario/Rabbids crossover adventure game
In 2010, Ubisoft Paris had explored proposing a crossover between the Mario franchise and its own  franchise. The game was conceptualized as a "subversive, self-aware take" on the Mario franchise and concept art was produced depicting Rabbids kidnapping Bowser as Mario chased them. According to an anonymous Ubisoft employee, the pitch was possibly rejected by Nintendo before it was formally shown. According to Ubisoft employee Davide Soliani, this attempt is unrelated to Mario + Rabbids: Kingdom Battle.

Mario's Castle
Mario's Castle was a game announced for the canceled "Project Atlantis" portable system. The only known report of it was in an issue of the gaming magazine .

Mario's City Deluxe
Mario's City Deluxe was a possible sequel to Mario's Time Machine, offhandedly mentioned on one of the developer's personal webpage.

VB Mario Kart
The German magazine Big N claimed that a Virtual Boy installment of the Mario Kart series, tentatively named VB Mario Kart, was in development. The only known media report of it is Big N's August 2000 issue, which listed it among various other canceled Virtual Boy projects.

Yoshi tech demo
IGN Pocket posted a screenshot of a presumed tech demo featuring a Purple Yoshi in a forest in a behind-the-back perspective as blue and red spider-like robots resembling severed segments of Mechawiggler attacked him. No other information about this alleged tech demo arose, however.