I absolutely adore this, I got the fourth ending on my first playthrough, this entire novel knows how to make people emotional.
It's rare to see a close representation of how grief can affect someone, it's even rarer to see somebody address how scary it can be for a person to know how long they have left.
The background, character design and the music is what drew me in the most! Not to also forget how good the writing is, you can tell every word and sentence had a thought behind it. :D