* AnimationAgeGhetto: Somewhat. It's recommended ages 5 to 7 on Netflix, despite the whole "vikings attacking and murdering an entire village" thing.
* AnticlimaxBoss: [[spoiler:Crom Cruach. Despite being an ancient Celtic god who destroyed Aisling's entire family (and possibly species), it gets about a minute of screen time and is promptly defeated by ''a piece of chalk''.]]
* AwesomeArt: The entire film is full of beautiful art that at first seems simplistic, but actually has a lot of details when you look closely... [[RealitySubtext much like the art]] in the [[https://en.wikipedia.org/wiki/Book_of_Kells Book of Kells itself]].
* AwesomeMusic: The entire soundtrack is great, courtesy of composer Bruno Coulais and Irish band Kila, but Aisling's Song is particularly noteworthy and regarded by some as the film's high point.
* EnsembleDarkhorse: Despite getting less screen time than Brendan and Aidan, Aisling is by far the most popular character in the film, even finding her way into [[http://www.empireonline.com/features/50-greatest-animated-characters/default.asp?film=45 Empire's list of 50 best animated movie characters]]. Compare the [[http://upload.wikimedia.org/wikipedia/en/a/ac/The_Secret_Of_Kells_Promo_Poster.jpg original theatrical poster]] to the [[http://www.imdb.com/media/rm4181888768/tt0485601 post-Oscar one]]. She also had the honour of [[http://www.youtube.com/watch?v=ZtHXICLmaW0 going to the Oscars in 2010]] when the film was nominated for Best Animated Feature. WordOfGod says [[http://whitefangkakashi300.deviantart.com/journal/There-and-Back-Again-387372034 here]] that Tomm Moore's thinking of doing a short film on Aisling or Pangur Ban, but he's hesitant about it because of people's head-canons.
* ItsShortSoItSucks: Perhaps the most common complaint with the film. The movie features a rich story and world with monks, a wall, a sacred book, fairies, Vikings, and an EldritchAbomination, but packs all of it into 75 minutes of screen time.
* JerkassWoobie: Abbot Cellach [[spoiler: post-attack, after he's been left broken by his guilt of not being able to protect his people and Brendan.]]
* {{Mondegreen}}: What Brendan prays on the stone in the forest. The subtitles say "Oh no, it's hard enough," one can hear it as "I know eternal love," and the DVDCommentary mentions that it's a prayer in Irish, which doesn't make sense with the English subtitles...
** It's the opening line of the Lord's Prayer in Irish: "Ár nAthair atá ar neamh...". The subtitles on the UK DVD just say ''[[EvenTheSubtitlerIsStumped [Prays in Irish]]]''.
* ShownTheirWork: Played with. The first ink Brendan is sent out to gather materials from is based on a [[http://web.ceu.hu/medstud/manual/MMM/ink.html real medieval recipe]] for gall ink; the "berries" are actually used cocoons for a type of wasp. But the resulting ink is [[ArtisticLicense actually black]].
** Aisling is shown to be frightened of the monastery's cross in the courtyard and is unable to enter the tower where Brendan is. Fitting, since she's a fairy and her people are slowly being pushed out and forgotten as Christianity spreads across Ireland. Fairies in Irish folklore were also unable to enter buildings unless specifically invited, thus the use of Pangur Ban to free Brendan from the basement.
*** And, as mentioned above, the lavish detail the animators paid to the Book of Kells is gorgeous, and looks like it could easily be an excerpt from one of the pages.
* StrawmanHasAPoint: Abbot Cellach's obsession with building his wall over preserving the books and his decision to forbid Brendan to go to the forest are portrayed as well-intentioned but ultimately misguided. And there's no doubt that [[JerkWithAHeartOfGold he's not the best at expressing his affection towards Brendan]]. However, on the other hand, when Brendan does go into the forest, he's attacked by wolves and would have died if the local representant of the FairFolk didn't come to help him. So the abbot was perfectly justified. Cellach's decision to protect the present (with his wall) instead of the future (the books and their knowledge) can seem justified in a time of invasions. And it's worth mentioning that, had he not lived in a world where Northmen are apparently unstoppable subhuman monsters, an invading army would have thought twice before attacking a heavily fortified location.
* VanillaProtagonist: Brendan, not much to him except that he's nice and brave.