Comment by badsectoracula

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.