Tbh I don't have too many ideas ab this one but I'll try.

0:00
The video fades out of black to reveal some kind of knot-puppet type thing. It's hanging by some wires, and is moving, so either there's wind or somebody/thing just moved it, the second being more likely.
It sort of reminds me of the french "doudou", this rabbit head attached to a cloth plushie every french kid seems to have had and munched the hell out of at one point (not me though lol x]). It has a sort of folkloric design and it looks handmade. The image is in surprisingly high quality in comparison to the following videos, it goes all the way up to 2160p (eugh data pollution x[).
The audio starts with a slowed down version of some tune. I feel like I heard it again later in the second gameplay footage, either the guitar guy or maybe the distorted sounds that are heard when the player goes up the stream in the tunnel >> TO CONFIRM

0:10
Video switches to a view of a green hat on someone's head. Not sure if it's someone though, it feels more like a doll or something given the lack of movement and the hair that looks plastic-y.
That hat is decorated with a folkloric band and fake flowers. Now I don't know much about types of folklore and whatnot, but this hat does feel leprechauny irishy to me. However it might just be the color effect which is mostly green and orange.
I feel like I've already seen figurines that give off the same vibe. Those that you'd find in your grandma's home. I'll try to find images. The hat also looks dusty af, like it's been sitting there for a while.
Something like that except leprechaun lol

0:16
Fade out of black onto the face of the very first human being we see!!!!
The camera zooms out. It's the eyes of an elderly looking person and they are filmed upside down. At this point they don't seem to be thriving. We can't even tell if they're alive. If they are though, they seems to be looking up as something, possibly the knot-puppet thing?
I can't see anything in the reflexion in their eyes.

woop will continue later, remembered i got shit to do. fuck responsabilities noooo