If there is a platform so ideally suited to the point and click adventure game, it is most certainly the Nintendo DS. And the Phoenix Wright games are a fairly decent example of this. The graphics are quite pretty for all the size of it, looking somewhat similar in style to the Broken Sword games, using anime style character art which blends fairly well together.
Now I can't say I'm hugely impressed with the quality of the writing. There seems to be a lot of focus on writing the mystery itself, and not quite enough on the involved characters. The game descends into utter silliness at many points that it ruined the experience somewhat, especially when working on cases with a serious tone. For the third case it is forgiveable, given that the majority of suspects are circus performers. I'd expect a few quirks. But in the last case, which has a particularly serious tone, it is rather grating. I really wanted to poke the stylus through Mrs. Oldbag's head every time I had to speak with her.
On the other hand, despite the bouts of silliness, I can't fault the cases themselves. The mysteries have a lot of depth, and are very interesting to investigate and try to solve. Unfortunately, aside from a few central characters, most have little depth, and function as little more than clue dispensers. It's not to say they aren't interesting characters, and integral to the story, they just don't have a lot to them. They tend to have one strong defining characteristic and little else.
The gameplay is where the game really shines though. Excepting the first case which functions as something of a tutorial, the cases are very involved and require a lot of investigation and thought.
The investigation stage has you examining the crime scene and interrogating witnesses. They may be reluctant to share though, requiring you to break 'psyche-locks' by presenting pieces of evidence which contradict their claims. It's a nice gimmick, and makes some of the characters feel like they have a little depth, as you delve into their past and try to draw their secrets out.
The courtroom scenes are much more difficult, as wrong moves can lose you 'life', so guessing randomly at every stage isn't in your best interests. You have to cross-examine witnesses, pressing them for pertinent information, and eventually present a piece of evidence whenever you spot a contradiction in their testimony. In general the difficulty is fairly consistent, but there were a few occasions where the contradiction was so trivial I failed to spot it, or I understood the contradiction, but couldn't figure out what to present to prove it. And the last case just gets plain confusing towards the end (you'll see when you get there).
The game is pretty difficult, particularly in the courtroom stages. You can guess and bluff a little, but sooner or later you'll have to provide some proof. You do really need to examine your evidence and think about it to understand how to proceed. Some parts require you to click on a specific area of the evidence to indicate your point. e.g. clicking on a map to show where a suspect was located. It's another nice gimmick, and I think the extra difficulty is well suited to the extreme linearity of the game.
Overall, it's a solid and enjoyable game. The gameplay is challenging and fun; shame it is so linear, there's not much replayability. The cases are interesting and well written, though they'd do far better with a bit more depth for the secondary characters, and some toning down of the misplaced humour. I wouldn't buy a DS for the sake of this game, but if you already have one, it's worth checking out, because despite it's faults, it's good fun.