I don't think I can say it any better than you.... So, I'm just here to say that I also finished the game and share the same feeling as you.
This game is bitter sweet in its own way and, for me, that what makes it memorable. I played few otome VNs myself and I can also understand that this might not be everyone's cup of tea, especially to those who's playing to seek for relieve in the typical (or twisted) otome happy ending after completing the game. Well, this one certainly doesn't give you that. However, I love it because the characters and plot were so realistic until the end. This game makes me re-think about what defines a happy ending (or any kinds of ending) in the real world.
Have you also tried different Houses while having a relation with the three of them? There're slight differences in the ending texts which I think shifted the ending's atmophere ever so slight, yet intersting.
Anyway, thank you for voicing the appreciation...I'm basically here just to say that we're in the same boat and glad that I'm not alone.
I think this game is awesome and unique in its own way. I've played it thoroughly and am glad that I bought it with the full price.
Thank you Argent Games! I personally looking forward for this kind of game from you.