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.