I didn't mind the sad endings, despite how much sympathy I felt for everyone, I felt this could only end bad the moment we got the first dream. The "best" way I could've seen this game ending would be Mercredi being locked up in a mental institution for probably the rest of her life.
And yeah, I really do wish we got to know the characters a bit more, I loved all of them except for Mercredi's mother obviously. I hope to get that chance in this next game.