- Alternate Character Interpretation: Velma is here pretty much the only one going against the grain by still maintaining her skepticism. Is she the Only Sane Man in this movie or just in blatant denial with cynicism her only defense mechanism?
- Author's Saving Throw:
- Flim Flam is aged up, probably because his status as a young kid contributed to his The Scrappy status.
- Daphne's appearance looks a lot more like her and in-character with her fashionista tendencies, as a complaint for The 13 Ghosts was that her character design looked too unrecognizable to be the same Daphne that we've often seen.
- The very creation of this film is pretty much making up for the fact that The 13 Ghosts of Scooby-Doo itself was Left Hanging for a very long time.
- Fanfic Fuel:
- Flim Flam somehow developed his own monster hunting shop somewhere between the end of 13 Ghosts and now.
- Scrappy is nowhere to be found in the film; what would've happened if he actually was in it? The same also applies to Weerd and Bogel, as neither are present in this film either.
- What would've happened if Velma did open the Chest of Demons?
- Rescued from the Scrappy Heap: Flim Flam is probably one of the few characters in the franchise who was an even worse scrappy than the Trope Namer himself. In the movie, he's revealed to no longer be a hustler and has a legitimate business, sold his products to his close friends (without swindling) and his voice actor was pretty well received over all.
- Shocking Moments: Double notion on two different sides of the fanbase. People who regard The 13 Ghosts of Scooby-Doo as a show either largely forgotten/unknown or known as being So Bad, It's Good would at long last be receiving a Fully Absorbed Finale via the DTV series as a total surprise. On the other when a leak was found a Scooby movie had the title "Curse of the 13th Ghost" there was some mild speculation it could be this only for a few days later much excitement/rejoicing when it turned out to be exactly what they had been expecting.
- Take That, Scrappy!: Scrappy-Doo for the most part has been left out of the film, but he did get a reference which Velma seems to deny knowing him. It isn't clear whether we are supposed to take this as a direct Take That!, a sign that we are supposed to understand Velma isn't to be taken seriously or just as a meta-joke that he's not here (something 13 Ghosts did a lot of). The later reveal by Word of God that Tim Sheridan did try to work Scrappy into the script may imply it's more likely the second or third rather than the first.
- Tear Jerker: In a meta sense, Scrappy being missing. The writers wanted to have him in, but Warner Bros., apparently still wary of how the older fans would react, put the kibosh on it. Thus we have an opening sequence...but with Scrappy's presence completely expunged. To add insult to injury, when Flim-Flam brings him up in the climax, Velma asks curiously, "What's a Scrappy?"
- They Changed It, Now It Sucks!:
- Some hardcore fans aren't going to take some of the changes here that well which really should have been expected, not helped with the below mentioned Wasted Character for Scrappy.
- The explicit supernatural trappings of The 13 Ghosts being given the Maybe Magic, Maybe Mundane treatment. Especially since there have been blatant supernatural beings in the franchise before — the first four movies, the live-action films, and Mystery Incorporated, so there's really no need for it; what makes it more egregious is Vincent's crystal is explicitly supernatural (not even Velma can explain that one away) so making the nature of the Chest and its contents ambiguous is pretty much pointless other than making Velma's character annoying.
- Tim Sheridan confirming that the newer movies are canon with the first four movies (Zombie Island, The Witch's Ghost, The Alien Invaders, and The Cyber Chase), in spite of how many retcons this would have to do in order to make it work, especially how it ignores the well-liked concept of the Gang being adults and instead keeps them as teenagers.
- They Wasted a Perfectly Good Character: Some fans are disappointed that Scrappy-Doo doesn't have any involvement in the film aside from being briefly mentioned by Flim Flam, when the film could've, as was done with Flim Flam, taken the opportunity to have Scrappy Rescued from the Scrappy Heap.
- They Wasted a Perfectly Good Plot: Maybe not as harsh as that, but to make a movie sequel to a series with an unfinished story and then end this movie with a Maybe Magic, Maybe Mundane ending that in itself might not be conclusive just reeks of confusion. Unless mind you this isn't the last we see of some of these plot elements.
- Fans hungry for more of an emphasis on Shaggy and Daphne's relationship in the 1980s Scooby-Doo shows, of which 13 Ghosts is one of them, were left short changed here. It isn't really touched on all that much in the movie, and the two only get a few scenes together separate from the rest of the gang.
- Unexpected Character: While the movie largely came out of left field, the fact that Flim-Flam, a character very much hated by the fanbase (and to the point even the showrunner, Tom Ruegger, hated him) is in the movie was very surprising.
YMMV / Scooby-Doo! and the Curse of the 13th Ghost