Described as "a master at climbing and archery", Ryas, the game's protagonist, is initially equipped with a hunter bow which can be used to defeat the hostile robots he encounters.

Ryas' older brother Urid decided to climb a nearby mountain, the Sunspear, in order to find the cause of the machine attacks but he has failed to return.

Upon reaching the top, Ryas finds a sign left behind by Urid indicating he is following a Thunderjaw to the nearby peak Talonreach.

Upon defeating the Thunderjaw, Ryas shuts down a transmitter that was acting as a lure for the machines, and finds another sign left behind by Urid showing he has gone off to the settlement Mother's Tears in Nora territory.

At Mother's Tears, he discovers that Urid is tracking the rogue Oseram engineer Asera, who is plotting on using her newly developed lures to send an army of machines against Carja.

He returns to Dawn's Grasp to report to Marad, who orders him to intercept Asera's Tallnecks at Eagle's Fall while Urid recovers from his wounds.

[13] While criticizing how some portions felt like a tech demo, IGN praised the visuals and haptics for adding to the experience, "It’s a real showcase for the PS VR2 right off the bat, with huge spectacle blending with small detail".

[24] Horizon Call of the Mountain sold 6,027 physical units during its first week of release in Japan, making it the 16th best-selling retail game in the country.