The good news is that Mario Kart Tour is still bound for smartphones, and barring another delay, it's still slated to ship in 2019. However, Nintendo is now anticipating a summer release. The extra time will be used to improve the quality of the game.
"In the smart device business, Mario Kart Tour was scheduled to be released this fiscal year, but in order to improve quality of the application and expand the content offerings after launch, the release date has been moved to summer 2019," Nintendo stated in its most recent earnings report. "As we endeavor to develop future planned applications, we will also focus on continued service operations for applications that have already been released to that consumers can enjoy playing them for a long time."
It's not clear which direction Nintendo will go with Super Mario Kart. The company could charge a flat fee and continue to support it with future updates, or it could charge for downloadable content, such as new racers and tracks. We'll just have to wait and see.
"Although this is very regrettable, we must let you know that the current development progress has not reached the standards we seek in a sequel to the Metroid Prime series," Nintendo's senior managing executive officer Shinya Takahashi said. "We have determined that the current development status of the game is very challenged, and we had to make a difficult decision as a development team."
"We have decided to have the producer, Kensuke Tanabe, work in trust and collaboration with the studio that developed the original Metroid Prime series, Retro Studios in the United States, and restart development from the beginning," Takahashi added.
It doesn't appear that Mario Kart Tour is in the same shape of disarray as Metroid Prime 4 was, but the bigger point is that Nintendo is highly critical of quality standards, and rightfully so—Nintendo has way more many good games under its belt than bad ones.