* AwesomeMusic: The whole soundtrack is awesome enough to warrant [[AwesomeMusic/UnderNightInBirth its own page]].
* CrackShip: Merkava/Vatista is oddly popular despite their interactions in their arcade ladders being less than friendly.
* ComplacentGamingSyndrome: A LOT of people have been using Phonon nowadays ever since the release of Exe: Late[st]. Earlier versions of Exe: Late involved the trinity of Gordeau, Waldstein and Merkava.
* EnsembleDarkhorse: With how much fan-art Vatista gets, you'd swear she's far more relevant to the plot than she actually is. In general, she's loved for having a [[{{Moe}} cute]] [[ElegantGothicLolita design]] along with having one of the most unique movesets in the game. [[note]] She has charged attacks for ''every'' possible directional input. [[/note]]
** Not to be outdone, Merkava is also quite popular.
** The game as a whole is this for Creator/ArcSystemWorks. Despite getting considerably less publicity than the likes of ''Franchise/BlazBlue'' or ''GuiltyGear'', Under Night In-Birth still enjoys very positive critical reception and an active and dedicated fanbase that would love for Arc and French Beard to give it more love, with plenty wondering why Exe: Late[st] hasn't been ported yet, until 2017. Then comes the question whether it will be brought to West or not. It's status as a darkhorse made it surprising that it was chosen to be part of a [[VideoGame/BlazBlueCrossTagBattle massive fighting game crossover]] alongside ''Franchise/BlazBlue'', ''VideoGame/Persona4Arena'' and ''WebAnimation/{{RWBY}}''.
* {{Fanon}}: While the late arrival of a story mode leaves many questions about the world and the cast unanswered, Hyde is commonly portrayed as a SupremeChef that's frequently shown serving food to the other characters.
* FanPreferredCouple: Even though Hyde is heavily promoted as being in a tag team with Linne, alot of fans are far more interested in his relationship with [[RobotGirl Vatista]] instead, [[RoboShip romantic]] or otherwise. It helps that most of the scenes involving Hyde and Vatista together are either [[SugarWiki/FunnyMoments hilarious]], [[SugarWiki/HeartwarmingMoments sweet]], or both.
* LauncherOfAThousandShips: Hyde. While the clear front runner is [[MeetCute Vatista]], Hyde has also been paired with [[ChildhoodFriendRomance Yuzuriha]], [[SempaiKohai Orie]], [[HoYay Seth]], and [[RescueRomance Linne.]]
* MemeticMutation: Nobody wears panties. [[https://www.youtube.com/watch?v=oMXl4L3Viak This video]] is a bit of proof.
* {{Moe}}: A good majority of the female cast are this, but [[RobotGirl Vatista]] and [[GenkiGirl Yuzuriha]] are notable examples.
* MostAnnoyingSound: Of course, Hilda with her NoblewomansLaugh.
* TheScrappy: Nanase is commonly hated for being an UngratefulBastard towards Hyde, while looking and acting like a stereotypical {{Tsundere}} in a game otherwise clean of anime cliches. People also tend to find her voice annoying.
* TierInducedScrappy: Quite a few...
** Gordeau, due to reaching damn near GameBreaker status via the reach on his attacks. He gets nerfed in Late[st].
** Chaos is often on the low-end of the spectrum, due to how little he has in the way of reversals and being unable to command Azhi Dahaka while under pressure himself.
** Waldstein is a Grappler character that is generally held to be the second-best character in the game. YouCanPanicNow.
** Merkava is usually part of the trinity of the best characters in the game, alongside Gordeau and Waldstein, but his darkhorse status protects him from fan backlash a bit.
** Akatsuki, due to his hindered physical range on his normals which prevent him from playing a decent footsies game compared to everyone else. This was before most of his buffs in Exe: Late[st].
*** The above examples have been mostly mitigated in Late[st], due to greatly buffing and improving most of the cast.
** Phonon, ever since Exe: Late[st], where she's used very frequently due to her long range and solid hit-confirms, and is also stated to have the range of Gordeau and the combo potential of Eltnum.
* VanillaProtagonist: While Hyde is well-liked by the fanbase [[NiceGuy for]] [[SirSwearsALot his]] [[HotBlooded quirks]], Linne, the other protagonist, isn't nearly as popular with the crowd, since many find her personality lacking. While she's not ''hated'', she's often forgotten about in favor of the more colorful cast that's supposed to play second-fiddle to her.