As a precursor, I would warn people that this review is from an irredeemable player of the visual novel. FSN is based on a visual novel that I adore and as such my review comes from a fan that has the original source to compare it to.
Fate/stay night is the story of the Holy Grail War, a secret competition held between magicians to obtain a device that will grant them any wish. Magicians summon Servants, spirits of heroic beings from myth and history, to do battle against other magicians in the hopes of attaining the Grail. Shirou Emiya, an amateur magus with no knowledge of the Grail is fatefully swept up into the war when he accidentally summons the Servant Saber, strongest of the seven Servant classes. Shirou becomes determined to win the competition to protect the unknowing public from the dangers the war presents in a bid to make true his dream to become an ally of Justice.
Like its origins, FSN is an interesting mix of action, fantasy, romantic comedy, and horror, though the show focuses on the former three than the horror aspects. Also like its origins as a visual novel, the series leans heavily early in the story on the audience’s interest in the Servants and their origins: discovering the identities of these mythological beings is part of the charm of the show, as is how they interact with each other and the world they have been summoned into. The latter half relies upon the audience’s familiarity with the tropes that the show is something of an exemplary example of, including the tsundere magus Rin Tohsaka, while also throwing in hints of the darker side of some expected tropes including the sweetly innocent childhood friend Sakura Matou.
The unfortunate thing of the show is that it tries to include material from the game that makes no sense without the game’s context. While the game had three separate routes for Shirou to take—focusing on the three different heroines of Saber, Rin, and Sakura—the anime centers around the Fate scenario and Saber’s story, but attempts to include material from the other scenarios. It also has issues with justifying some of the points in the source material: many a critic may complain about Shirou’s lack of common sense early on in the show, which is centered around staying true to his actions in the visual novel that make little sense without the inner thoughts Shirou has before taking those actions.
The animation of the show is decent, though as is common with many Studio DEEN series, the flow of the show is broken by some of the animation techniques and shading issues common now to other animation groups. While not bad, the animation suffers from a specifically DEEN look, which also somewhat dates the show even when it was initially released, similar to the studio’s later release Higurashi no Naku Koro ni. The animation style lends itself well to the surreal and often upsetting horror elements of the show, though bogs it down in the everyday and more comic aspects, which FSN focuses on more than the horror.
Musically, the series stands out, as composer Kenji Kawai often used themes from the game and expanded on them to maintain some of the feel and mood of the show. The first opening is a remixed version of the opening used in the game, while standout themes like “Emiya” and “The Sword of Promised Victory” make use of being orchestrated beyond their game BGM origins. New music composed for the show are a perfect complement and often evoke the exact right mood to given scenes.
As an adaptation, the show is adequate and potentially most of the audience will completely miss any comparative issues to the original source. Fans of the game generally accept it, unlike earlier TYPE-MOON visual novel adaptation Tsukihime, which suffered from all of FSN’s problems without many of FSN’s well-done aspects. Recommended and enjoyed, but I’d play the game first if given the chance.