Nintendo's Mario Kart Tour for iPhone jumps off track, delayed until summer 2019

The postponement was made "in order to improve quality of the application and expand the content offerings after launch," the Japanese company said in its quarterly earnings. Such delays are relatively common in the game industry, since developers can discover major bugs at the last minute, or realize that certain gameplay mechanics need to be improved.

Nintendo has said virtually nothing about "Tour" since announcing it exactly one year ago. Its partner on the game, DeNA, at one point said the title will be "free-to-start," without elaborating on what players might have to pay for.

"Mario Kart" is one of Nintendo's most successful and long-running franchises, dating back to 1992. Gamers race as various characters in the "Super Mario Bros." universe, using power-ups on the track to gain speed or sabotage opponents.

The company has been cautious about stepping into the world of phone and tablet gaming. While eager to tap its popularity, especially in Japan, investing too deeply could risk lucrative console sales.

There are only four Nintendo games currently on the App Store, namely Super Mario Run, Fire Emblem Heroes, Animal Crossing: Pocket Camp, and Dragalia Lost.