Early on, JavaScript libraries like gamepad.js were necessary for basic features like button mapping, but this is no longer the case. The W3C specification for gamepads has been through several iterations over the last few years.
I’ve written about television experiences previously, but I think gamepad support is a great addition for any web app designed to function in the living room.
For many individuals, this is the preferred remote control for watching movies and television shows. Secondary to games, a gamepad could also be used as an alternative input device in the context of the “10-foot experience,” when users are sitting far away from a large screen.