I downloaded it and tried to get it running in Mini vMac, but after spending some time down the surprisingly-familiar rathole of trying to figure out how in the world I transfer a runnable version of StuffIt into the emulated world, I gave up. If anyone manages to produce a .dsk image that has the executable demo on it, I'd love to see it.
Apparently this is video of a demo running on an 8mHz Mac Classic. It is 414 KB and written in assembly. Which is awesome.
Current Music: Hecq -- Hypnos I (Distant Fires) ♬