Yes, these aren't books -- they're games for the Nintendo DS. However, they fall squarely into the interactive fiction genre, so I feel reasonably justified in including them here.
You play Phoenix Wright, a defence attorney in a near-future world where the legal system has been radically simplified: the trial for each case may take no longer than three days. Your job is to prove your clients innocent. The game alternates between investigation -- where you wander around the crime scene searching for evidence and talking to witnesses -- and court sessions, where you get to cross-examine witnesses and spot holes in their testimony, which must be revealed to the court by asking appropriate questions or presenting evidence.
While the concept's pretty interesting in itself, it takes good writing to make an IF game work, and Phoenix Wright doesn't disappoint. The cases are entertainingly complicated and replete with clichés of the detective genre (no fewer than three of the cases feature the victim writing down the killer's name before they die, for example). Sometimes you can't be certain what's going on until the final clue pulls everything together; sometimes you'll be dead sure but unable to prove it to the judge. You'll also encounter plenty of red herrings while searching for evidence -- and you'll need to be prepared to bluff your way through the trial when you don't have the evidence you need.
The downside is that the story is entirely linear; there's generally exactly one way to do each of the things that must be done, and goals must almost always be achieved in a specific order. This is particularly awkward during the investigation segments, where (unless you're much better at second-guessing the authors than I am) you'll often find yourself showing every piece of evidence in your inventory to everybody you can find in the hopes of provoking a bit of dialogue that'll unlock the next bit of the plot. I also found that a couple of times I had guessed correctly what was going on, but needed to present the wrong piece of evidence first and have Phoenix go through a different theory in order for the right one to occur to him.
In general, I get the impression that the authors hadn't played much IF, and certainly hadn't played much good, modern IF, since they fall into a number of the standard traps. Text is presented slowly, a character at a time; you can usually tap the screen to get it to make the whole text appear, but this doesn't always work, and sometimes you'll miss an important line by accidentally tapping twice (and there's often no way to go back). Only one saved game is allowed, you can't save while selecting evidence or during some cut-scenes, and you can't restore without turning the console off and back on. The connections between locations are inconsistent, and in some bits of the story you spend a lot of time bouncing between different locations, which gets tedious when you have to remember how to get there.
In the cases where you do get a choice about what order to talk to people, the game will often assume you're doing it in a particular order, so (for example) your sidekick will often suggest you talk to someone you've already spoken to. Since you search for evidence by moving a cursor around a picture of the room, you'll generally need to use the standard graphical IF tactic of sweeping the entire screen for hotspots. There are separate but similar interfaces for browsing evidence and presenting evidence, so you'll sometimes enter one when you meant the other. The second game has a number of spelling and grammar errors in the text. And so on; these don't make the game unplayable, but they've been pretty effectively stamped out of modern IF, and a bit of extra work would have rendered the game much more polished.
Actually, I think I would have preferred the game as an early-90s-style text adventure with sidebar graphics; the ability to read text in large chunks and look back up at the history would be very useful, and I'd rather type commands than fiddle with the DS touchscreen. Perhaps a project for a fan remake (or fanfic) at some point?
The game was originally written for the GBA, and the fifth case in the first game was a bonus one added for the DS version. It takes about twice as long to complete as the others, the writing is of a significantly lower standard, it's not consistent with the continuity of the other cases, you gain a new (and more annoying) sidekick, and the authors added a number of irritating new game mechanics -- for example, you have to put the pieces of a broken vase back together. It's still fun to play, but I would have preferred it if they'd done a flashback to an earlier case instead, as they did in the later games in the series.
Anyway, I'm making it sound like I didn't enjoy the games, which definitely wasn't the case -- back to stuff I liked!
I think most players would agree that it's the characters who really make the game. Phoenix himself is joined by assistant and medium-in-training Maya, her older sister and fellow ace attorney Mia, equally ace prosecutors Edgeworth and von Karma (two thereof), hard-bitten detective Dick Gumshoe, the world's most easily-manipulable judge, and a host of other regulars. Each character has a distinctive "voice" and backstory, and you'll grow to care about all of them during the games. Phoenix's friends do seem to get into a surprising amount of legal trouble, but this is hardly a problem unique to the game, and it does provide for plenty of interesting character development.
The artwork is brilliant: nicely-realised manga-style characters with lots of variation and some entertaining animations; detailed and clear backgrounds for each location; and evidence including documents, objects and photographs. The characters are frequently very cute (if you don't feel guilty the first time you provoke the "sad Pearl" animation then there's probably something wrong with you). The game takes advantage of the DS's dual screens to present a full-screen illustration separately from the evidence browser, and occasionally splits a picture across the screens for more area -- good use of the hardware.
The music and sound effects are likewise excellent; there's enough different music that you shouldn't get bored of it during the game (and it's good enough to be worth listening to on headphones rather than through the DS's speakers), and the courtroom scenes are adequately provided with dramatic desk slams and shouts of "Objection!" and "Hold it!". (Since the DS has a microphone, you can in fact shout "Objection!" and "Hold it!" back at the game as an alternative to pressing buttons if you prefer.)
The game is full of wordplay and pop culture references; nearly every character name is a pun of some sort. The writing quality is generally very high. This is particularly impressive given that the game is a translation -- the original was in Japanese, and equally full of jokes, most of which have been transferred (or seamlessly replaced) in the English translation.
One interesting thing about the translation is that it's also a transculturation. The original game ("Gyakuten Saiban" -- "Turnabout Trial") was set in Japan; the translation is set in America. This feels a bit awkward in the first game, since many of the character archetypes and situations are very much idiomatic to Japanese fiction, and gets downright weird in the second game where one case involves visiting a traditional Japanese village. A number of changes to the plot and character backstories have been made to accommodate this, and as a result the continuities of the two translations are significantly at odds with each other. I'm not normally a fan of transculturation, but I can understand why they did it (if nothing else, it makes the jokey names a bit more believable), and they seem to have done a thorough and consistent job of it.
I thoroughly enjoyed these two games, and I'd strongly recommend them. Thanks to Jon for lending me the games, and Ian for lending a DS to play them on.