Nintendo's first mobile game (as opposed to app), Super Mario Run, will require an internet connection to work.

Speaking to Mashable, Shigeru Miyamoto explained the reasoning behind this.  In essence as Toad Rally, which lets you compete against friends, requires an internet connection Nintendo decided to make all modes require one to improve stability, probably at the expense of battery.

We wanted to be able to leverage that network connection with all three of the [Super Mario Run] modes to keep all of the modes functioning together and offering the game in a way that keeps the software secure. This is something that we want to continue to work on as we continue to develop the game.

The game is due to launch next week on iOS devices, before coming to Android some time next year.  In the mean time you can enjoy this recently released advert.