If there's enough room, you could add special palette indexes that stay
constant or diminish more slowly with distance. To give a glow effect for
lights, torches, etc. I always appreciated this effect in Quake.
EDIT: Oh nevermind. I guess brightmaps are more flexible.
I have fond memories of Planet Quake and also Blues News (for the latest
scoop). I remember it spawned a whole bunch of other planet sites. I think some
of them became part of GameSpy (or its parent company). I
probably moved on by then.
I like the idea but you could take it a step further and have just a core
virtual machine that you could attach virtual (input/output) devices to. So
then the canvas and audio would just be virtual devices that met some
specification. Or say for example, you just want to listen to an audio
playlist, you could attach an audio device, a keyboard and a terminal device
(for feedback). A canvas device wouldn't necessarily be required (if there was
no use for one). And it would be up to the user to attach the devices required
by an application, or at least the user would have direct control.
TLDR: QEMU but much simpler and only WASM need be supported.
EDIT: Oh nevermind. I guess brightmaps are more flexible.