The servers are experiencing heavy traffic. Your log-in request will be processed in the order it was received, reads a message that appears when the game is launched.
Nintendo did not respond to a request for immediate comment.
Bringing the Mario Kart franchise to smartphones offers the Japanese firm a chance to reverse a run of lackluster releases including this year’s Dr. Mario World, a reboot of a minor title which gamers criticized as unpolished. Since its 1992 launch, the Mario Kart series has sold tens of millions of units.
Mario Kart Tour’s release comes ahead of a number of games for Nintendo’s hybrid home-handheld Switch console designed to appeal to more casual players, including two Pokemon titles in November and island life simulator Animal Crossing: New Horizons in March.
Analysts expect those games to drive demand for the Switch Lite, a handheld-only version of the device that launched on Friday retailing for a third less than the original.
Nintendo, which is yet to incorporate the new device into its forecasts, expects to sell 18 million Switch units in the year ending March.