Social Canvas is probably the world's largest multiplayer game installation. It functions like most tile-matching video games except on a much, much larger scale. It was created in 2018 and installed at the MGM Cotai in Macau.
Visitors to MGM Cotai can quickly join the game by scanning a QR code and submit entries by sending messages to a dedicated WeChat channel.
These entries are then displayed in “The Spectacle”, MGM’s term for the world’s largest area of permanent indoor LED screens that makes up their lobby and casino entrance.
In addition to the scale of this installation, it is also unique in that it is truly interactive. Guests are allowed to directly participate in the game, creating an shared experience for all.
MGM's write up is here. The featured videos show an overview of the project and a demo of the project in action.