Oh my gosh, you guys. I just played through Professor Layton vs. Ace Attorney, and my heart is full. I will divide my thoughts into three sections, the not-spoilery-at-all, the spoilery-for-games-in-these-respective-series-that-precede-this-one, and the spoilery-for-this-game, so that people may read and cease reading according to what they have played.
And I must note, I have not yet played Azran Legacy nor Dual Destinies, being as I believe in playing these games in the order they were originally released, which meant we had to get our hands on the fan-translated rom of Investigations 2 before we could play this one! And that was really great too! Anyway, so should anyone happen to comment on this, do not dare to breathe a hint of spoiler for Azran Legacy nor Dual Destinies, or I will hate you almost as much as I love Prof. Layton. (and block you from my place here.)
Chapter One: Not Spoilery at All
OH MY GOSH. I have been crazy waiting for this game for... how long has it been? Well over a year, over two I think. Ever since that first trailer was released. I think I was still in college at the time, which would make it three years! I was Not disappointed in the slightest. I had thought the main draw would be simply that it is a crossover, a game featuring both the sets of hero and sidekick from those amazing series, and that was going to be enough for me. But it's so much more!
It's a sterling example of everything a crossover should be, to its fullest and greatest potential. It's not just that it has the main characters from both series. The gameplay--the gameplay--the unique, it-wouldn't-be-those-series-without-that-gameplay of those series, they mix it so seamlessly and so distinctly and so dramatically! Layton has previously shown downright masterpiece use of gameplay to perfectly express story in a way nothing else could, notably in the final puzzle of Diabolical Box; they show again that they know how to make the gameplay take your breath away with its dramatic storytelling power just as much as the writing and cinematography. And how they mix the souls of the two series, not just in the gameplay, but in the recurring themes and paralleling incidences and character types... it feels like a Professor Layton game, and it feels like an Ace Attorney game, wholly and without conflict. It's almost like... a hypostatic union! And the transcendental themes, Meenah! The admiration and the awesomeness! That's really all I can say whilst remaining not spoilery at all, so.
Chapter Two: Spoilery for Games in these Respective Series that Precede this One
Um, now that I come to it, I can't think of much to say here that doesn't reveal content of this game as well. Hmm. Well! I can harp on the transcendental themes already established in the series that made them so perfect for crossing over, and how great these characters already were!
For a long time, I had been seeing these two series as exemplifying a hero in pursuit of/embodying one of the Transcendentals, and the kind of wondrous/aweful impact that makes on the lives of others. With Ace Attorney, it's Truth, and with Prof. Layton, it's Goodness. (I am still looking for a DS game series that exemplifies the pursuit/embodiment of Beauty; let me know if you know a good one that fits that bill!)
The Professor and Phoenix are, it becomes clearer and clearer as their stories proceed, truly great men, heroic and masterful, and change the lives of others in a heart-stirring way that happens with really intensely virtuous people. Don't think virtuous in the sense of the cariacatures crafted by those who laud virtue but are misguided and are really lauding niceness or respectability or sentimentality, nor those crafted by the malicious who revile virtue. Not lacy piety nor puritanical boringness. That is not what virtue looks like.
Real virtue blazes, bears suffering, and kicks ass.
And thus do these men.
Now, of course the Professor is seeking Truth along the way, and usually uncovers it with earthshaking results, but it is as a figure of Goodness, particularized in the ideal of the Gentleman, that he really has a transformative impact on people.
Likewise, Phoenix within his games actually stands within a set of three men, three friends, whose vocations reflect the three Transcendentals, and among those he's actually the one that matches up with Goodness. But the overall theme of the series, and what he's always seeking, and the true purpose of being a lawyer which he reveals to those who had lost it, is Truth.
This goes to show how the Transcendentals are united; indeed the power that the Goodness or Truth of a person devoted to it has to draw and rescue and create bonds with others, so powerfully shown is these games, is a kind of Beauty. So they are all One. Phoenix and the Professor have these incredible impacts on people because of this, drawing them out of darkness, sometimes even when they don't know it, and forging bonds of admiration and friendship and Love. These relationships, these bonds, these Loves, with their respective sidekicks, friends who were in peril of their souls, the women they love romantically, and others, make these games so very powerful.
And so then comes this game, in which
Chapter Three: Spoilery for This Game
(as well as for the preceding)
they have such an impact, and create such a bond, with each other.
Admiration.
I don't think it gets that much attention, but I'm seeing lately how crucial it is. When trying to write a romance, for example, I find it works best, and comes closest to the kind of romance I treasure in fiction, when the admiration is paramount. Many romances in fiction just concentrate on desire, and that is blah. I mean, desire is wonderful if you have the good romance established, but it's the pediment, not the foundation.
In the case of both these men, they each have in their respective stories a romance that are among my favorite romances in all of fiction. They each love a woman who is so worthy of admiration, astonishingly virtuous in turn. Self-giving to heartbreaking extents. Then the desire is there, as the crown rather than the base, and thus it is ennobling rather than base. As a side note, it seems to me very fitting that Phoenix's beloved is incredibly physically beautiful, whilst the Professor's is certainly pretty, but not outstandingly so. I'm not sure why that so fits, but it does.
But anyway, admiration is not only crucial to romantic love, but also to heroic comradeship. And in this game, Phoenix and the Professor develop admiration of each other that is so awesome, and their drive to protect the innocent, and defy the powerful whilst still having compassion but no compromise... It's glorious.
Huh, as I didn't name names, I actually wasn't very spoilery of the preceding games in that preceding chapter and last few paragraphs.
Well, that pretty much scratches the surface of my highfalutin high philosophical love of these games. Now to some specific squee-points!
I'm really glad they didn't do something I was maybe expecting: I was thinking that maybe the Professor and Luke, and Phoenix and Maya, would get sucked from their respective story-universes, as separate universes, into the magical world of Labyrinthia. But no, instead it is established that they have always occupied the same universe, the same continuity, and continue to do so afterward!
Oh man. One thing that really got me excited was figuring out at which point, between which other games, this takes place. I was overjoyed to see that without ever out-and-out saying, they made it precisely clear. That is to say--the folks on the wikis might not agree with me on this (I dunno, I have not checked because of Azran Legacy and Dual Destinies spoilers) but--it is clear to me that it happens after Diabolical Box, before Unwound Future, after Trials and Tribulations, before the stuff that happens in flashback in Apollo Justice. The befores are obvious, because SPECIFIC SPOILERS Luke is still in England and Phoenix is not disbarred. The afters are a little less clear, but is implied in Maya saying "Zvarri!" and that at the end it beckons right into Unwound Future.
It's really amazing how strongly they link it to the before and after, especially in the Ace Attorney context in the most heartrending scene of the game. When the Professor and Maya seem to have been killed, (and even though you know they can't be, it sure as heck seems so and feels like it) Phoenix's grief is made all the more compelling by remembering that Godot had only just revoked his blame of Phoenix for the death of Mia, and then, in a heartbreakingly genius use of the crossover gameplay, the first unavoidable puzzle that Phoenix ever solves is him beginning to drink, as he does in Apollo Justice.
And Luke there, the both of them bearing so much... oh gosh. See eightcrows picture for better expression than I can say of this incredible scene:

END SPECIFIC SPOILERS
The voice acting was good. Christopher Robin Miller has always been amazing as the Professor. The Phoenix voice actor bugged me a little at first--it was mainly the Objection. I still kinda think they should have kept the old Objection sound file, even if it wasn't the same guy, just for the sake of that heartgasp recognition. But he totally proves himself as you go. The Maya voice was kinda annoying, but fortunately her most powerful lines weren't voice-acted. The voice actress for Espella did some astounding performance.
The music is amazing. I ordered the soundtrack before I'd even finished the game. The adapting the super-dramatic Ace Attorney themes in ways to make them even more dramatic, the so emotional and exquisite use of the Fey sisters theme, the dour new puzzles theme, and the epic combinations of Ace Attorney and Professor Layton stuff... Oh wow.
I want to do so much fanart.