[tspng]

If I set the scale value (150) to roughly the ppi of my screen (4k 27"), I can see the effect. You should see the rotating stars only in a small field of view (fov) where your eyes are focused and all other stars should seem to remain still.

[cornonthecobra]

My phone screen is a bit over 500 ppi. I tried it full screen across the entire range that it's in focus (I'm mildly nearsighted), and I could just see the things spinning across the whole field if the pinwheels were big enough to see motion at all.

Maybe it doesn't work on small/AMOLED screens?