Hi, thanks for playing!
This is a case where more testing would have been ideal.
You only need most of the hearts (20, if I remember correctly) for the "good" ending. If you find less than that, you get the other ending.
I thought it would be nice not to have to find every single one and still get the better ending, but as you and some other players have proven, players tend to think you need to find them all, which makes things needlessly confusing.
I hope that makes sense. We'll certainly keep this in mind for our next game ^^,
-Jay