Silent Shark

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

Cleaned up / textured with Nano Banana: - patrol zone map - shipping lane map - sea state list

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.