This is the kind of visualisation that obvious in retrospect, but I don't think anybody's done this before. Very nice.
I think the only change I'd make really is to give the top layer and obviously different colour so you can view from the top and see the current configuration. Currently it just looks confusing because e.g. a - oscillator looks like + instead.
The “fading” animation (what the top-down view here looks like, minus the shrinking due to perspective) already did exist in the 1980s, just not the 3D-zation of it.
Not to detract from the Show HN entry, but I made this back in 2012 to play with 3Delight's API and implicit surfaces: https://vimeo.com/manage/videos/56307994
The one posted to HN is better in several ways, but I was mainly interested in learning about 3Delight.
I'm really curious what bigger hashlife patterns would look like (metacell, etc.) but the visualization gets tricky with that many objects.
Came here to say the same: remarkable, just make the very top layer hard white, or outlined, or something that contrasts with the falling history.
Here's one from 2018: https://www.reddit.com/r/math/comments/9xfquc/3d_visualizati...
One from 2 weeks ago: https://www.instagram.com/reel/DUxkEiWDS-q/
I'm sure there is much older.