Nintendo has confirmed that Super Mario Run will only be playable with a working internet connection. This means that players will not be able to play the game in airplanes or other locations where no internet connection is available.
Mario franchise creator Shigeru Miyamoto explained that the reason for this limitation is related to game piracy. Nintendo fears that the game will see widespread piracy if it doesn't include a connection to Nintendo's servers.
It is surprising that the game features the DRM system, because Super Mario Run is, for the most part, a singleplayer game. The game does contain some online capabilities in the form of Toad Rally, but it does not feature enough content to justify having an internet connection constantly available.
The inclusion of an always online DRM system will most likely hinder a higher number of legitimate players than the number of gamers that will be prevented from playing a pirated copy of the game.
According to Android and iOS software developers Nintendo's always online DRM system can be easily patched within mere minutes. If the always online DRM system is patched, it will most likely be more popular than the legitimate version.