I'm flattered to receive such praise from a veteran in this community. Thank you for this comment, it made my day! During the development, I had very little to show, because I was more focused on writing. I didn't allow myself to spoil too much of the art. Even with the very little, I'm glad it drew your interest. The project has taught me so much and I was far from giving up on it.
I assume you were following the countdown? I hope you got to sleep a bit :'D The 2 CGs you mentioned are probably from the normal ending. The CGs are listed in order. Zeikun's route is programmed a bit differently than the rest; his endings branches from the last menu. Experiment with the choices to get different endings and achievements.