When I played Stray for the first time, I quickly noticed that the strange writing used for chapter headers could actually be translated from the English titles. Together with my dad, we created this alphabet:
In order to create this alphabet, we started by translating each of the chapter titles, and using context to guess some missing letters. A handful of titles are slightly different, but most are the same.
From here, we were able to translate signs all across the map, filling in the rest of the alphabet. This alphabet has only one case, and uses English punctuation.