I'll be otherwise vague to not spoil people, but I wanted to get the fourth ending before commenting---I really really loved this! I adore the sincerity of your writing and the respect and care that you use to address the different subject matters of the story.
Another aspect I wanted to comment on was that this was a rare case where the "bad endings" felt narratively satisfying--though I was very happy to work for the fourth ending, the other three endings still felt fully realized and (albeit much sadder) satisfying conclusions! Any single one of them on their own would've been a powerful ending but all four of them really make it shine :]
On a less writing-heavy level, I also really love your character designs and environmental art, they're super distinct and really lovely! I had a wonderful time playing this, and I'm excited to see what you do next ^^