It's 'E' for everyone and includes fantasy violence and even some language. Here's the rating summary in full:
"This is an action-adventure game in which players assume the role of Aloy as she protects her home from invaders. From a 3/4-overhead perspective, players traverse platform environments, interact with characters, and engage in melee combat against LEGO cultists and robotic dinosaurs. Players use punches, bows, and explosives to defeat enemies that break apart into LEGO pieces. Battles are often fast-paced, accompanied by explosions, impact sounds, and cries of pain. Boss encounters involve more protracted combat with larger robotic dinosaurs. The word "a*s" is heard in the game."
At the end of August, a page on PlayStation's official website mentioned how LEGO Horizon Adventures would be arriving on 14th November 2024, after the original announcement said the game would be arriving in "Holiday 2024".