The game follows Professor Layton, Luke Triton, Phoenix Wright and Maya Fey as they attempt to solve the mystery of Labyrinthia.

The game has two main styles of gameplay, Adventure and Witch Trial, which feature elements from the Professor Layton and Ace Attorney series respectively.

During Adventure segments, players can explore various environments, conversing with characters and examining background objects in order to find clues to solving the mystery of Labyrinthia.

The control scheme is similar to the one introduced in Professor Layton and the Miracle Mask, in which players navigate the environments by moving around a cursor on the screen.

In the Witch Trial sections, players take control of Phoenix Wright as he cross-examines witnesses in order to defend his client.

Level-5 announced that they would release downloadable content for the game, including a new storyline written by Shu Takumi, which would be split up in 12 episodes.

The downloadable story episodes, which are considered non-canon and frequently break the fourth wall, take place one year after the events of the game and feature Layton, Luke, Phoenix, and Maya returning to Labyrinthia for a visit.

Phoenix Wright, an American defense attorney in London as part of a legal exchange, is assigned to Espella's case.

Layton and Maya awaken outside town, finding a settlement populated by Shades, hooded worshipers of the Great Witch.

Darklaw is revealed to be Belduke's daughter and Espella's childhood friend Eve, who blamed Arthur for her father's suicide; she lured Layton into Labyrinthia and sabotaged the story to get revenge, and was forced to include Phoenix when he unwittingly got involved.

[15] On September 25, 2010, the game was outed on Twitter when Jiro Ishii of Level-5 accidentally tweeted to Jin Fujisawa of Square Enix, "Huh?

[16] The mistake was quickly covered up by Jiro Ishii who tweeted later that day that, "A misunderstanding seems to be spreading, so let me say that I'm currently working only on Time Travelers.

[19] Hino recognized that fans of both series would "want to see a showdown" between the lead characters as well as sections where the two "join hands and take on a really big challenge".

[19] Even though Professor Layton vs. Phoenix Wright: Ace Attorney is a crossover, Hino and Takumi both see the game as more of a legitimate installment to their respective series rather than as a spin-off.

Takumi was initially hesitant to adopt this feature, but later came to appreciate it, recognising that the 3D visuals allowed developers to "present the action from different angles and really [expand] the freedom of expression" within the courtroom segments of the game.

[23] Yo Oizumi and Maki Horikita, who voiced Professor Layton and Luke in previous games, reprised their roles, whilst Phoenix and Maya were voiced by Hiroki Narimiya and Mirei Kiritani, who also played their roles in the Gyakuten Saiban live action film.

[31] During Japan Expo 2013 in France, when asked about a localization of the game, Level-5 CEO Akihiro Hino said that "something was in the works", but that he couldn't talk about it at the time.

The soundtrack to the game was a collaborative effort between Professor Layton series' composer Tomohito Nishiura and newcomer Yasumasa Kitagawa of Capcom.

Nishiura and Kitagawa arranged and orchestrated the music with the help of Yumiko Hashizume and Norihito Sumitomo; whom had both previously worked on the Professor Layton series.

Awarding it a score of nine out of ten, Oliver Jia of Game-OST.com praised the album as "the soundtrack that fans of both series have been wanting for years.

"[35] Luna Lee of RPGFan Music similarly responded favorably to the soundtrack, but criticized the tracks for being, "segregated into two camps and [having] few overlaps with one another.

"[36] Japanese pre-orders of the game included a special bonus soundtrack containing five musical tracks and a celluloid film strip containing select animation cels.

[37][unreliable source] The entire soundtrack was officially released on a 3-disc set as Layton Kyouju VS Gyakuten Saiban Mahou Ongaku Taizen (lit.