The Wraith Train: Illusory Domain

The developers describe how their game uses AI generated content like this:

游戏中的所有素材均通过AI生成，文字翻译、图像、音频、视频均有AI生成 All in-game materials are generated by Al.All text, imagery ,video and audio within the game are AI-generated.

Required on Steam store pages since 2024. It covers content that ships in the game, on its store page or in its marketing — Valve does not require a disclosure for AI tools used during development, so this says nothing either way about how the game was made. Check it on Steam.