The framing story is set in the 21st century and features an unidentified and unseen protagonist, who joins the Assassins as an initiate to help them locate the corpse of an 18th-century Templar Grand Master.

The game also introduces cooperative multiplayer to the Assassin's Creed series, letting up to four players engage in narrative-driven missions and explore the open world map.

Players who had bought the game's season pass (which was later made unavailable for purchase in response to the controversy) additionally received a free copy of another Ubisoft title of their choice.

It was followed in October 2015 by Assassin's Creed Syndicate, which continues the modern-day narrative, but has its main plot set in Victorian era London.

Examples include scaring a group of bullies by pulling out a weapon, "settling" a fight between two civilians by killing one of them, or chasing down a thief who has just pick pocketed somebody.

The player can renovate the Café by investing in upgrades, which change the building's interior and unlock new rooms, including a secret passage to the Assassins' underground hideout.

[6][15][16] Arno blames himself when his adoptive father is murdered, and so sets out on a quest of redemption that brings him into the Brotherhood of Assassins, where he slowly rises through the ranks, much like Altaïr Ibn-La'Ahad and Ezio Auditore da Firenze as seen in previous games.

[15][16][18] The era also features appearances from several historical figures, such as the Marquis de Sade (Alex Ivanovici), Maximilien Robespierre (Bruce Dinsmore), and a young Napoleon Bonaparte (Brent Skagford).

Accessing them takes Arno to various points of Parisian history, such as Paris' Belle Époque, or its occupation by Nazi Germany during World War II.

While playing through a memory of Jacques de Molay (Mario Desmarais), in which he orders a fellow Templar to hide his codex and sword during the sacking of the Paris Temple in 1307, the player is contacted by the Assassin Brotherhood through their agent, codenamed "Bishop" (Kate Todd).

Bishop invites the player to join the Assassins as an initiate, and presents an Abstergo video memo describing the capture of a Sage who contains precursor DNA.

During his investigation, Arno rescues François-Thomas Germain (Julian Casey), a silversmith held hostage by the acting-Templar Grand Master Lafreniere (Noel Burton).

While searching the Tuileries Palace for potentially damning letters from Mirabeau to King Louis, Arno encounters Napoleon Bonaparte, who helps him escape.

Arno realizes that Germain plots to spark a mass revolt against the King, and assassinates the Templars aiding him with Napoleon and Élise's help, rekindling his relationship with the latter in the process.

Falling into a drunken depression, Arno languishes for months before he is found in Versailles by Élise, who convinces him to return as Paris is tearing itself apart during the Reign of Terror.

Arno confronts Germain, who is empowered by de Molay's sword—a Sword of Eden—and pursues him to the Templar crypt underneath the Paris Temple, where Élise soon arrives to help.

The game ends with Arno explaining how his understanding of the Creed has changed, and promising to watch over Paris and keep Élise's memory alive.

During his search, Arno encounters tomb raiders led by Captain Philippe Rose (Taylor Price), a subordinate of Napoleon, who wishes to retrieve an artifact—an Apple of Eden—from a Precursor temple under the city's church.

Arno decides to stay in France, and contacts the Brotherhood to deliver the Apple to Egypt, far from the reach of Napoleon, who is arrested for desertion and treason.

The leak revealed that Unity would feature a new location and time period, Paris during the French Revolution, a new assassin, and that it would be released in late 2014 on PlayStation 4 and Xbox One.

[40][41] On the delay, Vincent Pontbriand, senior producer at Ubisoft, said, "As we got close to the finish, we realized we were near the target but still needed a bit more time to hone some of the details to make sure Assassin's Creed Unity is exceptional."

[50] Chris Carter from Destructoid gave the game 7/10, praising the new movement system, likable lead characters, iconic setting, smooth animation and improved draw distance.

[47] Marty Sliva from IGN gave the game 7.8/10, praising the recreation of Paris and ambitious ideas presented in the multiplayer, but criticizing the unrefined stealth, weak story and lack of a strong lead character.

He stated that "the true new-gen Assassin's Creed game is a gorgeous, entertaining, and successful proof of concept for what lies ahead for the series, though it isn't what I'd call revolutionary.

[65] In response to the issues, Ubisoft announced that it would halt sales of the game's season pass and Gold Edition, and offer the first downloadable content (DLC) pack, Dead Kings, for free.

[69] This news has possible connections to Ubisoft's third quarter financial report, which was released on the same day, and states that Assassin's Creed Syndicate had a "slower launch than expected.

Mélenchon has expressed his criticisms in multiple media appearances, telling the New York Times that, "Smearing the great revolution is dirty work that aims to instill the French with even more self-loathing and talk of decline.

"[74] Without mentioning the criticism specifically, in an interview published on October 6, 2014, by Time, the game's creative director Alex Amancio said "What we actually try to do, and I think this is just a personal belief that we have, is to avoid reducing history... We try very hard to portray things as factually as possible.

Clark also looked to the way Amancio and Therien answered the question and felt how they referenced "how much the team wanted to include playable female characters suggests... that this is probably a decision which hasn't gone down well internally.

[87] Additionally, former Assassin's Creed game designer Patrice Désilets commented that Amancio's reasoning was valid, but that Ubisoft should put in the effort to let players have gender options.