That is definitely understandable! I am quite glad you enjoyed the game. If it helps, it is definitely a purposeful omission. Quotation marks are often not used by myself when writing even typical fiction and, with this dialogue heavy IF, I believe their omission to fit the disconnected tone.
Some indication, however, is the separation of paragraphs. No two characters speak in the same paragraph. I hope that note clears things up if it is a confusing matter for anybody else, as well.
Thank you for playing! I found the game you submitted to this game interesting, as well.