Matter MazeBall: Element Trials

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

This game uses content created with the assistance of generative AI. Some of the game's artwork and visual assets, along with its store page and marketing text, were produced with generative AI tools. The core gameplay — levels, mechanics, and the real-time 3D visuals rendered by the game engine — is hand-designed and code-generated by the developer. No generative AI content is created in real time during gameplay; all assets are finalized and reviewed before release.

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.