Small nitpick. Tried logging in simultaneously with a desktop and a phone to make it wasn't BSing, and it was actually sending moves/fruit correctly. Yes, appears to. However, found out phones don't update on touchmove. Only on final touch.

Be nice if it used:

  const [sendMove, getMove] = room.makeAction('pointerMove')

  window.addEventListener('pointermove', e => sendMove([e.clientX, e.clientY]))

It's part of the Pointer Events API and provides a unified event model for handling mouse, pen/stylus, and touchscreens.

If necessary it can then use "PointerEvent.pointerType" to find the actual type.

https://developer.mozilla.org/en-US/docs/Web/API/Element/poi...

Otherwise, neat capability, and there's at least several different concepts it seems like it would be enabling of. Mapping / GIS, you could see where other people are browsing on somewhere like Google Maps. Maybe leave little markers that fade with time. Temporary file sharing where you broadcast a list of available files after logging on and peers can send requests. Dropbox-esque send yourself stuff with a home system that's always logged on. Computer-aided design (CAD/CAE/CAM) or stuff like blender/photoshop, work on models/images together. Obvious stuff like word/excel. Field Service Management, collaborative service calls.

Admittedly, also enabling of botnets, darkweb, and other such ideas. However, such is the nature of a lot of these types of technologies.