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

Generative AI was used as a production tool to help create and refine some static visual assets, including illustrations, backgrounds, CG images, promotional artwork, and Steam library images. It was also used to assist with translation drafts. All final assets and text were reviewed and edited manually before being included in the game.

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.