History YMMV / HappyHalloweenScoobyDoo

* SurpisinglyImprovedSequel: In contrast to the controversial ''WesternAnimation/ScoobyDooAndTheCurseOfThe13thGhost'' and the despised ''WesternAnimation/ScoobyDooReturnToZombieIsland'', this movie earned very positive reviews, thanks to Maxwell Atoms's strong direction and a more cohesive mystery and comedy.

* FridgeBrilliance: Another reason the gang failed to recognize the Sheriff as past enemy Cutler Toe -- aside from lack of a beard, hat covering the baldness, and altering voice and demeanor -- the picture of the unmasking from his monster disguise shows that the gang found Toe's oufit so disgusting that none of them could stand to even look at him directly.

* JustHereForGodzilla: Even if you don't regularly watch the Scooby-Doo movies, you may decide to give this movie a go if you're a Batman fan to see the appearance of ''ComicBook/TheScarecrow''. Or you're a fan of Bill Nye and/or Elvira, either of them could be strong selling points for the movie as well.

* AuthorsSavingThrow:
** Seems the writers of ''Return to Zombie Island'' realized the wasted potential in not fully using Elvira, so this movie seeks to rectify that.
** For those taking issue with Velma's behavior in the previous two movies, she gets called out here and also comes to realize how close-minded and stubborn she became.
** The film isn't a continuation of a prior story or incarnation like ''Curse of the 13th Ghost'' and ''Return to Zombie Island'', likely due to how [[ContestedSequel controversial]] both films were with handling elements of the prior material. The film is also [[BroadStrokes looser]] regarding franchise continuity, mixing and matching elements rather than trying to awkwardly {{Retcon}} older stories. [[spoiler:The film does, however, resolve a plot thread from both of those films, that being the Sheriff turning out to be EvilAllAlong.]] According to Maxwell Atoms in the WhatCouldHaveBeen entry, this decision was made before he came on board.

* TheyWastedAPerfectlyGoodCharacter: Even ignoring those who don't have that much of a problem with Scarecrow being the main villain (see below) for a second, many fans were still disappointed to find out that despite being heavily advertised as such that his total screen time only amounts to five minutes, with his only major moments being at the beginning and then towards the end of the second act, feeling like a bit of a waste especially since Creator/DwightSchultz is clearly giving it his all as well as the interesting WorthyOpponent dynamic he has with Velma. The most common speculation being (like most behind-the-scenes aspects of the film) ExecutiveMeddling, specifically from the DC Comics side of things.
* TheyWastedAPerfectlyGoodPlot:
** The premise of Scarecrow leading an army of monster pumpkins to wreak havoc is an entertaining idea, but Scarecrow is a RedHerring. The movie being your standard lighter-toned ''Scooby'' fare means that we don’t get what could’ve been a genuinely creepy, scary film.
** The revelation about an earlier script has lead to some criticism about the film's lack of covering some elements from the previous two movies. The Mystery Machine's random comeback only to be taken out early seemed weird. The promotion of Bill Nye and Scarecrow into important roles also doesn't suit well given that the movie may have instead have given other Scooby characters a chance to return. The reveal of [[spoiler:The Sheriff as the bad guy but to be someone we had never heard of before also seems like a very weak choice given hundreds of MythologyGag options there could have been]].
* TrailersAlwaysLie: The trailer makes it seem like Jonathan Crane, aka the Scarecrow, is the BigBad. Instead, he's being framed by another party, who's been plotting against Mystery Inc. since ''WesternAnimation/ScoobyDooAndTheCurseOfThe13thGhost''.

* WereStillRelevantDammit: The movie really gluts itself on late 2010s/2020 slang, catchphrases, and elements. When Velma is explaining the mystery at the beginning, Daphne keeps spouting phrases like “basic” and “womp womp”; air drop and mic drop are used during Bill Nye’s introduction; and Scarecrow even calls the gang the “avocado toast generation.”

* FridgeLogic: Another reason the gang failed to recognize the Sheriff as past enemy Cutler Toe -- aside from lack of a beard, hat covering the baldness, and altering voice and demeanor -- the picture of the unmasking from his monster disguise shows that the gang found Toe's oufit so disgusting that none of them could stand to even look at him directly.

* EarWorm: Good luck getting "Look At Us Now" out of your head any time soon!

* InferredHolocaust: The town of Crystal Cove is presumably destroyed by collapsing into a cataclysm, possibly killing god knows how many people, but this is never commented on...aside from Bill Nye's odd claim that they shouldn't have collapsed due to a lack of fault line despite what the audience witnesses.
* JustHereForGodzilla: Even if you don't regularly watch the Scooby Doo movies, you may decide to give this movie a go if you're a Batman fan to see the appearance of ''ComicBook/TheScarecrow''. Or you're a fan of Bill Nye and/or Elvira, either of them could be strong selling points for the movie as well.

** The film isn't a continuation of a prior story or incarnation like ''Curse of the 13th Ghost'' and ''Return to Zombie Island'', likely due to how [[ContestedSequel controversial]] both films were with handling elements of the prior material. [[spoiler:The film does, however, resolve a plot thread from both of those films, that being the Sheriff turning out to be EvilAllAlong.]] According to Maxwell Atoms in the WhatCouldHaveBeen entry this decision was made before he came on board.