It depends on the speed of the CPU - if you look at the archive at https://www.pouet.net/prod.php?which=85227, you'll find a DOSBox config specifically for this demo. If you run it in DOSBox you can fiddle with the emulation speed by pressing C-F11 and C-F12 and you'll notice the speed of the animation change.

Later: Your question made me wonder what the performance of virtual 'target CPU' is - the 'cycles' setting in the config is 20000 and there's a rough estimate of what these numbers translate to here

https://www.dosbox.com/wiki/Performance

So it looks like it's something along the lines of 'a 486 in the prime of its life'.