From my playthroughs so far, this visual novel easily has the best writing I've seen. It's not uncommon for game jams to forgo proofreaders and for you to catch typos and syntax errors. I really enjoyed the metaphors especially! They helped really capture the vibe of what you were aiming for.
The art is loveable and the animations on the second half were very well done. I especially liked the sound fx and the dreary tune that plays throughout the game. It does well to set the mood, as well as conceal the twist.
As for said twist, I do believe it could've had a bit more build up to it. I knew that she had "episodes", however I think a few clues about the dangers of said episodes could've been expanded upon. Obviously the mystery needs to be a mystery, however proper build up and subtle hints make it all the more satisfying. That said, I'm not particularly good at solving mysteries...
Also, I'm not one to bring up excess assets, but I wish Jessica had more of a role. SHe was there for one scene and that's it. You could easily have tied her in to the end somehow, mainly leaving clues for the audience. Even though we knew she didn't know of her problems, there's a lot of potential for utilizing her to up the ante.
Good luck with your jam project!