Well, this isn’t something that I spotted in my play through but a YouTuber by the name of ‘YongYea’ has discovered a small, but pretty cool Death Stranding/Kojima Productions Easter egg in Horizon Zero Dawn.
There’s a collectible in the game in which the thumbnail is the logo of Kojima Productions.
Further to this, the description for the item reads:
“This object is valid only for curious merchants. Six blocks of oxidised metal twisted from one cable”.
Now interestedly enough, this necklace belongs to the character that Norman Reedus plays in Death Stranding.
Kojima’s Death Stranding is using the same engine as Horizon Zero Dawn, called the Decima engine.