When Apple stages a keynote presentation, the company’s latest products are always front and centre. But at this week’s reveal of the iPhone 7 and Apple Watch Series 2, the show was stolen by a stout plumber (fictional, no less) and his elegantly understated creator.

Apple’s chief executive Tim Cook welcomed Shigeru Miyamoto, Nintendo’s star video games designer, onstage to a deafening response, which grew louder on the news that a Super Mario game was on its way to the iPhone - the first time Nintendo’s most iconic character will feature in a smartphone game. Offstage, Nintendo’s share price rose 13pc as investors rejoiced at the sign that after years, the Japanese company had embraced the smartphone world.

The game, Super Mario Run, where the player helps Mario jump over ditches, bouncing on enemies and collecting coins, arrives on the iPhone in December. So why has Nintendo taken the momentous decision that now is the time for its most valuable character to cross over from console to smartphone games?