Thank you very much. Unfortunately, maybe because I didn't sleep last night, I forgot to mention that I don't read Japanese. None of these seem to be translated, at least from what I can see on vndb. I am starting to study Japanese though so I'll keep this list for when I get a better hang of it.
I realized Narcissu might fit the bill, though. At least from what I can remember, it handles the impermanence of life, if anyone is interested (I already played it).
I wonder if this kind of thing doesn't go well with western audiences since none of the ones you were so kind to list have any translation. Such a shame.