We did something like that with an Amiga bouncing ball demo (on linux or Macs) back in the day (two decades ago, probably)

I think it was using a wide master screen that the terminals connected to via vnc, displaying different parts of the master screen. Only three or four screens wide, though, and not optimized for user interaction. But a live app nonetheless.

Me too! Making it do interactive things is actually quite trivial since we went for the socket.io web approach rather than using something specific to video streaming. I'm imagining two QR codes on either end, players join and play a wide game of pong. Maybe with phone gyroscopes for controls.