Suggest me a book that’s kind of meta?

I LOVE ergotic fiction (i.e. House of Leaves, S.) but whenever I look online for different books in the genre it recommends me the same ones over and over, and I find that many of them just have characterized narrator than actually playing with the format of being a book. What are some book that truly are meta? That play with formatting and expectations and are wild like that? Doesn't need to be any particular genre such as horror or mystery, any is great!