imo Other M was ok, nothing special, but like you said Nintendo intended to show Samus's softer side, but I think it didn't worked so well.
They show her as a weak character, everything is about the stupid baby metroid and not using her powers because Adam didn't allow it, she is supposed to be a strong character with a lot of self-confidence, she can defense for herself, and that's why I like the Prime series so much.
Also, what I really like about Samus is her mystery, not knowing much about a character can be a lot better than knowing all of his/her past (if it is executed well).
Nintendo and PC gamer