Mario Kart World has been in development for 8 years as Nintendo struggled to improve a 'perfect' formula
Briefly

Nintendo fans were skeptical about a sequel to Mario Kart 8 due to its enduring success. However, a developer diary revealed that Nintendo has been secretly working on a follow-up, Mario Kart World, since 2017. Initially intended for the original Switch, the new game aims to evolve the formula by introducing a large world map for players to explore. Producer Kosuke Yabuki emphasized that simply adding new courses wouldn't suffice, hence the more ambitious direction of the sequel.
"I felt that in Mario Kart 8 Deluxe, we were able to perfect the formula that we'd been following in the series up to that point, where players race on individual courses," says Mario Kart producer Kosuke Yabuki. "That's why, this time, we wanted the gameplay to involve players driving around a large world, and we began creating a world map like this."
What took things so long? Well, as it turns out, one-upping the most popular game in your modern catalog isn't easy.
Nintendo knew that it couldn't simply create new courses and characters and call it a day. Had that been the case, the sequel would have gone with a more iterative title like Mario Kart 9.
Read at Polygon
[
|
]