Completed the game following @BroCube's steps, and tried to decipher the text.
All text in the game can be decoded with a simple substitution cipher to English. Below is the substitution table.
(Not sure about Q. Every letter appears somewhere as part of a word except for Q.)
Text is written boustrophedon (every other line is mirrored). Adjacent words are separated by a vertical line. The end of a sentence is marked by a pair of vertical lines with a large gap between them. Emphasis (unsure; only seen in the shop) is also denoted by two vertical lines but with a smaller gap in between.