Unrealized Dreams: Warner Bros. San Diegos Ambitious Kart Racer Inspired by Mario Kart Goes Unseen

Warner Bros. was said to be developing a racing game reminiscent of Mario Kart, featuring characters from its extensive collection of intellectual properties, including Adventure Time, Scooby Doo, Tom and Jerry, and others. This kart racing game was in production at Warner Bros. Games San Diego, which was closed along with two other internal studios in February. The game was never officially announced by Warner Bros., and it reportedly underwent multiple revisions, shifting from a free-to-play cross-platform game to a paid PC-exclusive release.

WB San Diego’s Attempt at a Mario Kart-Inspired Racer

This information was shared by Colin Moriarty, who mentioned on his Sacred Symbols podcast on Monday that a former employee from WB San Diego contacted him regarding the unpublicized project. The racing game in development went by the codename «Moonlight» and might have been titled «WB Racers» or «XDR,» which stands for cross-drift racers, according to Moriarty’s source.

Similar to the lineup of Nintendo characters in Mario Kart, this game was intended to include Warner Bros. intellectual properties such as Adventure Time and Tom and Jerry. Moriarty claimed to have viewed gameplay footage from the title and noted that it was «heavily inspired» by Mario Kart, describing it as a «drift racer utilizing Unreal Engine 5, featuring stylized graphics and precise vehicle handling.»

The WB San Diego employee conveyed to Moriarty that the project suffered from a lack of clear «intention» and a «coherent approach,» and it experienced numerous changes throughout its development. Project Moonlight reportedly began as an online-only free-to-play game for PlayStation, Xbox, Nintendo Switch, and mobile devices. However, near the end of the development cycle, the Switch and mobile versions were dropped in favor of a PC version. Ultimately, the kart racer evolved into a paid PC-only title, with console adaptations on hold.

Reportedly, the game received a green light during the pandemic and was expected to be released through Steam Early Access. According to the insider, WB San Diego had over 100 developers working on the project, which «began to unravel last fall.»

Despite the extensive effort put into the game, it was never released. The insider mentioned that there was «considerable animosity internally,» as staff members at WB San Diego felt it was unjust that Player First Games, another Warner Bros. Games studio, managed to launch MultiVersus twice, while the kart racing game never came to fruition.

Last month, both WB San Diego and Player First Games, along with Monolith Productions, were closed after Warner Bros.’ gaming division recorded a loss of $300 million (approximately Rs. 2,627 crore) in 2024. The company also cancelled the Wonder Woman game that was in development and stated its plans to refocus on its «larger franchises» such as Harry Potter, Game of Thrones, and Batman, following a series of unsuccessful launches.