- Ass Pull: The Timmy Turner Loophole, for some. Basically, it was created so that Timmy would be allowed to keep his Fairy Godparents even after growing up. Even if it was justified in that Fairy World does owe Timmy big time for saving them on more than one occasion, it still came out of left field and undermined the point of the special, which was to have Timmy grow up.
- Broken Base:
- Cosmo and Wanda's CG designs. Some don't mind them, but others would've preferred them done in the show's old style, or anything if they flat-out hate the CG.
- Before the movie even aired, many fans reacted in sheer disbelief if not anger. Now that it has aired, some think it's flat-out awful, and some fans enjoyed it.
- The sequels were even more broken. Many saw there being no reason for other movies.
- Tootie's adult design has torn up the fanbases, especially Tootie fans.
- Ear Worm: "Lookin' Like Magic"
- Ensemble Dark Horse:
- Some admitted that they liked Magnate's assistant Janice, because she was the only one who actually questioned what Magnate was doing.
- Fanon Discontinuity: Some fans won't acknowledge it. Aside from perceived quality, a common reason is that it contradicts the Distant Finale of Channel Chasers, which shows Timmy indeed maturing and growing up while living a normal life. To fans satisfied with that ending, this comes off as a Happy Ending Override.
- Ho Yay: Between Crocker and Magnate.
- Moral Event Horizon: Magnate trapping Tootie in a cage and using a remote control to zap Cosmo, Wanda and Poof and drain their energy is bad enough, but it gets worse when he wishes for a bottomless ball pit that he wishes a random mook and Mr. Crocker down. Crocker gets better, though. The mook, on the other hand...
- Nightmare Fuel: Hugh J. Magnate's creepily smiling and giggling evil rabbit. Even though it was likely meant as a comical joke, it still manages to be this due to the high pitched laughter and human face on it, not to mention it came right out of nowhere, with only Magnate's Evil Laugh probably hinting at it.
- One-Scene Wonder:
- Jason Alexander and Cheryl Hines as human Cosmo and Wanda, much to the disappointment of many who felt they were much better than the CGI fairies with their TV voices that were used through most of the film.
- Vicky's scenes.
- Romantic Plot Tumor: Inverted, if that's even possible. Many people agreed that the romance between Timmy and Tootie is one of the few genuinely good things in this movie, with some wishing that the movie would've focused on those scenes entirely.
- Ship-to-Ship Combat:
- A large percentage of the people complaining and prejudging this movie are simply angered fans of other love interests such as Trixie, Vicky, or Veronica. This is not helped by the fact that the movie makes a point to establish that all other prior romantic moments on the show, besides Timmy being kissed by Tootie against his will, simply did not happen, and that Timmy has never truly loved any other girl.
- A character match-up quiz on the official Nickelodeon website strongly suggests that Tootie was the mystery mother of Timmy's children at the end of Channel Chasers, adding gasoline to an already white hot fiery debate, or perhaps dousing it with a splash of cold water, although some people just prefer not to think of this movie as the real ending to the series, as well as not taking the quiz seriously since this isn't Butch Hartman himself saying it.
- So Okay, It's Average: This is the general consensus for the movie. While no masterpiece, it's not the utter trainwreck people expected it to be.
- Squick: A twenty three year old man acting like a child, even if it is an act to keep beloved fairy godparents is kind of creepy. It becomes even more creepy when you realize that this Manchild is likely sharing a locker room and bathrooms with other ten year old boys
- Tainted by the Preview: There are fans who really dislike the idea of making a traditional Thick-Line Animation series into a Live-Action Adaptation. The few previews that were shown prior to the movie's premiere did little to alleviate those fans' doubts about this project. There are a variety of reasons for this ranging from Avatar: The Last Airbender's live action movie (perceived by people to have been done very poorly) to the fact that there is some Ship Sinking along with the fact that Timmy Turner never grew up and is now a creepy Manchild Even though the movie has now aired, the reaction still is mixed about it.
- Tastes Like Diabetes: For those who didn't like the movie (and even for some who did), the ending was this and for being a very predictable and cliché ending.
- They Wasted a Perfectly Good Plot: Timmy being forced to make a difficult decision between finally growing up with the love of his life or continue to live the way he is with the family he loves so much? Sounds like it could have made the perfect finale for the series. But alas, that is not the case.
- Unnecessary Makeover: The brief flashback to a live-action "young" Tootie is certainly more recognizable to the viewer than the live-action "adult" Tootie.
- WTH, Casting Agency?: Some of the cast.
YMMV / A Fairly Odd Movie: Grow Up, Timmy Turner!