Nintendo has filed a lawsuit against a U.S. maker of software that allows people to play games intended for its hugely popular Switch device on their PC or smartphone.

The company behind Super Mario, the Legend of Zelda and Donkey Kong is looking to clamp down on the operations of a company called Tropic Haze, registered in the U.S. state of Rhode Island, which owns and runs Yuzu, a popular video game emulator.

A video game emulator is a piece of software that you can download onto your PC or smartphone to play video games intended for a specific console, such as the Switch, PlayStation or Xbox.