Super great work. Although I am not familiar with Ancient history and name so I make a little bit research and found that all of those quote and towns' names has references. I really appreciate a game with reality reference and it helps players to dive into the game and feel more connection to it.
I played as the normal way and use usual word but surely players can make funny sentences. The potential of making funny outcomes and branch endings is obvious. The strength and intensity of the words upgraded really show how the skill of the bard improve and the content becomes more exaggerate as the time goes on. This really polished the game.
One big limitation of this game(you might also predict it when you design this game) would be it is a little bit hardcore to those non-English speakers since it greatly requires the understanding in English. Plus the story takes place in ancient Greek and the bard sings in poem structure so the sentence pattern would be much more unfamiliar as general non-English speaker usually learnt the modern English communication pattern. This would be a natural limitation comes along with text-based adventure game so I think there is no way to change it, while I suggest maybe adding a feature to classify the word would be friendly to the player to search the word. For example, I want to search the word quickly so I classify manually all words in noun, verb and adj/adv before singing the song. It may be better to have this kind of classifying system to help the player. Surely I assume you have more game experience and more familiar in text-based adventure game than me, still I would like to share a game called "文字獄" that published on steam https://store.steampowered.com/app/1035750/_/. It also supports English language and maybe you can find extra ideas or inspiration from this game.
An issue I encounter during the game: After I finish the longer song for wine. I pick up "frightening" word and want to put it in a bottom area, and when I release the mouse button, it just flies out the screen and I can't grab it back. But later on in Chapter 4 after dealing with the bandits, it upgrades to terrifying and both the "terrifying" and "frightening" words come back.
This is just a minor issue so overall I rate this game 5/5 and this deserves more people to play and rate it! How come there are only 6 people to rate it?