Nintendo considered completing Mario Kart 7 on 3DS by the end of this year "an act of emergency", the game's producer has admitted.
But several production designers were moved to work on 3DS launch title Nintendogs + Cats to ensure that game was ready for the handheld's release line-up.
Nintendo eventually called on the services of Metroid Prime Trilogy and Donkey Kong Country developer Retro Studios to make sure Mario Kart 7 was finished this year.
Nintendo previously stated Retro had helped design a Donkey Kong Country-themed course. It now appears Retro worked on revamping the game's entire 16 classic courses line-up, leaving Nintendo's team free to create the game's roster of 16 fresh tracks.
Mario Kart 7 is released next Friday in Europe. Alongside last week's Super Mario 3D Land, the two Nintendo titles are the company's big hopes of securing strong Christmas sales for its fledgling handheld.