Suggestions on how to license a "no-code" video game

Sorry in advance - I am personally not a fan of the term “no-code”, nor am I a fan of “no-code/low-code” itself. But, here we are…

I’m building a fun little project that is a point-and-click adventure game engine.

The idea is that the “game” will just be a folder full of images, audio files, and metadata to explain where to click on screen, what events happen, etc.
Then the game engine takes that metadata as input and spits out a playable game on the other end.

I intend to release the game engine under the GPL.
Inside the repository, I am bundling a small example game that can be used as a reference or additional documentation.

My question:

I’m asking since there is technically no code (just .png, .ogg, and .toml files only).
Is is appropriate to include the game content inside this repository under the GPL?

Are there other licenses I should consider using for what is effectively just metadata and media?