The idea for the Nintendo Switch came from a desire to combine "leisurely" video games with games designed to be played "deeply," general manager of entertainment Shinya Takahashi and deputy general manager of entertainment Yoshiaki Koizumi at Nintendo told Toyo Keizai Online (translation and article via Japanese Nintendo).
The two say concepting for the console began in 2012, after the release of the Nintendo Wii U platform. By the end of 2013, though, they add, the company decided on two core concepts that'd shape its next console: that of the two detachable Joycon controllers, and a console made to be played inside on a television and on the go.
"What we’re conscious about is that the gaming population is getting polarized into two," Koizumi said. "In the recent years, we are in a situation where [p]eople who want to play leisurely choose smartphone games, and people who play games deeply would play with PlayStation 4 and PC. The idea of combining the good points of smartphones and home consoles became the result of thinking a game that can be enjoyed by both audiences."
These ideas, they continue, presented challenges in terms of balancing the console. Koizumi said there was a high desire to make the console a demanding machine "with simply high specs by employing good memory and GPU." This philosophy was conflicted, though, by the company needing to make the machine small and portable.
"We need to consider the price and life time of batteries as well," Koizumi added. "Furthermore, there is a deadline in the development period, and development resources in our company are also limited. The most difficult part was on how to take an overall balance while we were getting entangled with all of those in complexity."
"We tested a number of variations for just the method of attaching the Joy-Con to the console," he continues. "Ultimately we settled with the method of sliding them into the rails on the console, but at the prototyping phases we tried a lot of methods like sticking them with magnets and putting them on dish-shaped parts."
During this development period, Takahashi says, there was "around five" different prototypes for the Nintendo Switch.
Since its release in March, the Nitnendo Switch has sold more than 10 million units. Furthermore, the company's tentpole launch title, The Legend Zelda: Breath of the Wild, topped many outlets' Game of the Year lists – including the yearly Game Awards.