敵国工場への潜入

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

Some in-game backgrounds and icons, as well as icons in the game preview thumbnails.

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.