To start with the conclusion, I liked it, but it felt very much as a reaction to the previous games. And that works out well at times, sometimes not as good. For example, the concept of the Dark Times of the Law was great, because it built upon themes of the previous games. Prosecutors who kill (Jin, Karuma), defense attorneys who fabricate evidence (Phoenix/Garyuu), the constant battles in court: yes, it would be logical to see that people would lose faith in the law. The Themis Academy and Ichiro were a great example, of people who tried to cheat the law. So yes, this was a great concept, and it tied very nicely to Naruhodo, because he was a big part of bringing this movement up in the first place: have him come back, and save Jin was great.
Also, Odoroki was a much better character here, because we finally were told something more about him, something horribly neglected in GS4. His ties with Aoi, their catchphrase daijoubu, it all worked IMHO. Also, how his bracelet reacted to Kokone, and how he started to get doubts about was 1) done well, 2) fitting his character, I think. It's a lot more believing in your friends/clients without any doubt (certainly considering that his own mentor betrayed him...). It makes him different from Naruhodo, in a good way.
I have said it many times now, but Kokone was horrible as a character. She was just too involved with everything. Being friends with Shinobu ties her up with two cases, one other case serves as her introduction and the last two cases she ends up being the defendant and the case is strongly tied to her (naturally) sad past. And that case is also one of the reasons for the Dark Times of the Law. Oh, and she has a new gameplay mechanic (which is praised as providing something new to the legal system), and is instantly the moodmaker of the party and she replaces Minuki in case two, even though it would make much more sense to have Yumemi's friend as your assistent. And you get to play as her. And not. YES WE KNOW IT KNOW SHE IS AWESOME. Jeez. Kokone is just too much present in the plot.
I did like the matrix thingy, though I think it would have been more logical for it to have been an investigation phase mechanic, rather than a trial mechanic. Everybody talks about evidence there, and no, 'I think you were a little sad, even though you should have been happy' is not really convincing. And then we have the judge in the last trial saying he thinks it adds something to the legal world, which sounded too much like the developer's words, rather than the judge's.
Having three attorneys, all with special powers was just too much for this game. It has severe problems with presentation: the game starts with Naruhodo's narration, but then it turns out the case 1's narration is done by Kokone, but you play as Naruhodo. Case two: narration Kokone/gameplay Odoroki. Last two cases? Mostly Naruhodo. It keeps jumping, and I really have to ask the question: did we really have to be Kokone? Does it add to the narration/presentation to the game if we keep jumping between characters? Do we really need to separate narration protagonist and gameplay protagonist?
The game is clearly a GK team game, with the overall theme. Like I said, I liked the theme, the presentation, not as much. With a big theme like this, it would have been better if they had spread it a bit more, instead of concentrating on the last two cases.
The cases were 'interesting' in both the positive and negative meanings of the word. Case two foreshadows a lot of the 'major' plot twists of case five for example (mask / ID tags as 'identity markers'. Case three finally shows the true implications of the Dark Times. Four and five however were strange. Four ends abruptly and gives you no resolution whatsoever. Five is just an extension and borrow heavily from GS1-4, GS1-5 (the child murderer, someone else being behind it, someone close being behind it, memory loss) and GS2-4 (hostage situation, someone communicating through proxy, an international sought criminal). Too heavily actually.
Case two and three were my favorite. I love youkai, which explains two, but there are some interesting elements like the rules of the village, the turnabout situation surrounding Great Kyuubi and the idea of a locked room mystery. With three, I liked the case itself as well as how it ties up to the overall theme.
Oh, and the usage of Minuki and Harumi was horrible. Minuki disappears almost immediately, shows her face one or two times and then ends up a hostage. Harumi was only needed to deliver the letter, and to tell a bit about the black locks. This, as well as Apollo's kickass growth are all reactions to GS4 I think, were a lot of people complained we didn't see/hear about of the old cast. In this case, Apollo was handled way because it did really add something to his character, but Minuki and Harumi were really nothing more than fanservice, and to be honest, I am not a very big fan of this kind of presented-as-important-but-not-really-important appearances. I'd rather have something subtle.