An interactive novel in which you try to decipher an ancient / alien language.
You constantly get “evidence” in the form of glyphs and drawings. The story follows roughly the same steps as how other languages were discovered (Linear B, Indus Script, Rosetta Stone, etcetera).
Over time, you should repeatedly get flashes of insight and be able to translate larger pieces of the text.
This feels like the ideal balance between an interactive novel, a traditional novel, and something more like a picture book or game.