In Super Mario Run, players tap the screen to make Mario jump over obstacles and enemies as he constantly sprints through various 3D worlds of the Mushroom Kingdom. It costs $10 for the full game, though the first few levels are playable for free. Also, make sure to find a strong internet connection, since Super Mario Run doesn't work offline, ostensibly in an attempt to combat piracy.
In its first four days on the App Store, Super Mario Run was downloaded 40 million times. However, Nintendo hasn't revealed how many players have actually thrown down $10 for the complete game. Either way, that figure is due to increase in March.