How many video games have a substitution cipher? It seems like a very common trope. Off the top of my head:
* Zelda (Hylian is a substitution cipher for Japanese kana)
* Final Fantasy X (Spiran language is just English letters, Al-Bhed is a substitution cipher with gameplay elements)
* Kirby and the Forgotten Land (the opening lyrics are even transcribed both in English letters and the substitution cipher right below them)
* Battletoads (Topian is a substitution cipher)
* Void Stranger (substitution cipher vaguely looks like Braille)
* Aquaria (the game actually comes with a normal English alphabet file you can just rename if you want to play it while being able to read the Aquarian substitution cipher)
This is so common. Has no one started a TV Tropes page about this?