Just finished Rin's bad and good ending last night. FINALLY. Still have the "true"/neutral one to do.
Here are my two cents, after having played through all routes except Lilly's (which I'm really looking forward to):
If I hadn't heard about it being such an emotional rollercoaster, I would've been surprised about the melancholia present in her path. At least, judging from Act 1 I wouldn't have suspected something quite like this. What also surprised me is the often-occuring lack of music, especially in Act 2 (iirc). Even moreso when thinking about her own theme, Parity (which I love to say the least). Of course this is due to the lack of uplifting moments during most of her path, so I guess it's only natural.
As for the plot itself, I found it especially tiring and emotionally draining due to Hisao constantly pointing out to just
how different the two of them are. ("Oh noez we will never be able to understand each other") Seriously, this got old real quick. I mean, in the end he still stuck with it, so why whine so much? Maybe I'm just weird, but I think part of the fun of being around Rin is not knowing exactly what is going on behind that emerald eyes of hers. She's a mystery, yeah, so DEAL WITH IT.
Then again, Hisao is pretty much a good example for the average person in her route, with all the mistakes that includes; if he was different, how could the writers have shown her issues to deal with her situation?
Speaking of "her situation": As far as I can remember it was never said explicitly, but is there some kind of specific mental issue she is suffering from? Asperger's is often mentioned in the forums, but I can't remember it being said in the game.
Anyway, despite the issues I'm having with Hisao's behavior and such, I want to say I really, really enjoyed her route. And the last line of her good ending seriously gave me watery eyes.
In short, writing, Art, choice of BGM: Amazing.