Awesome stuff, yet it was only voted 2nd in the competition (Revision 2016 64kb compo). Here's the winner (fermi paradox by mercury):

https://www.youtube.com/watch?v=JZ6ZzJeWgpY

The scenes with the moon being peppered with impacts (3:31) and what appears to be storms on Jupiter are beautiful.

As someone who was there: Darkness was impressive for sure, but not all that fun to watch, since it was mostly static dioramas, which the viewer can grok in a few seconds, and then it goes "oh and each one has a little jiggle too". Camera movement is minimal, and even when its there it doesn't expose anything new in the scene to the viewer. Additionally every scene is mostly faked with very obvious 2D shapes, meaning if the camera moved too much, the illusion would break. Lastly, the music was quite dull and not connected with what was on screen.

Fermi Paradox was also dioramas, but: Each one had had some engaging event happening, or at least well directed camera movements that exposed new visuals to the viewer over time or show-cased the full 3d nature of each scene. Additionally each scene had at least one well done graphics effect. The music was almost movie quality and in a few parts nicely synched up with the visuals.

How in the heck did they do that in 64kb

That is mind blowing.

Leaves quivering on a branch, realistic flames, realistic humans!

The water wasn't quite right but still.

Leaves quivering can be done with a simple sine that gets a value that is increased with a random delta with a different offset for each leave group (if you notice in games which have "wind", this is how it is done - the system exposes some knobs for designers to twist until things look good, but in general that is the idea).

The flames are very simple particles, the flame effect is probably the simplest particle effect you can do. The particle scene is blurred though before rendering the human figure, so the irregularities are not that visible.

The humans are simple black+white cutouts (they might be even stored as a single bit per pixel) with a small "light edge" on the side (most likely applied as an effect and not part of the data). It isn't very visible in the YouTube video because the compression smears a bit the scene, but if you run the demo locally you'll easily see it.

The intro isn't that high tech (compared to other intros of course), but Conspiracy are masters of presentation - the scene with the humans, leaves, mountains, house, etc wouldn't look as good as they do if it wasn't for the color grading, the camera motion and framing, the post processing and even the sequence the scenes are presented.

That was amazing! Many focus on a narrow presentation or style. That had all kinds of visual and mechanical elements to it that were done smoothly.