I personally think that the Loud House Movie is good, but it's kind of confusing, animation's rough and probably a little cartoony. (Note: Some of my reasons may be confusing to others, but this is just my opinion.)
Now, I think the reason why the Loud House Movie wasn't a good movie than we thought because Chris Savino got fired. I'm pretty sure that if Chris didn't get fired, he would've turned the film into a golden piece of Nickelodeon filmage.
Now, I want to talk about the plot itself. The reason why we have this film so Lincoln can finally be special and have enough spotlight like his sisters. He doesn't get a lot attention, like "Attention Deficit" and "Kings of the Con." And he is incredibly unsuccesful, in "Making the Case." The rising action could've been better, but that's just enough. Their time is Scotland is satisfying, but Lincoln is kind of unlikable, and that there is a dragon and ghosts? That's a reason why the Loud House is getting WAY too cartoony.
Now I want to talk about the animation. Couldn't the animation be better? The spin scene when Lincoln sees the duke's room, that was something. I swear it had shadows and lighting in the series, so I can take notice that the film was rushed. Back in the introduction, I said the film was confusing, how did Bobby make it to Scotland, how did Lucy get the ghost of Lucille back in HER AGE, and how was there a dragon? What about characters? The family is in character, but somehow Lincoln is pretty unlikable somehow, as he is the main character of the movie and the series itself. At least he learns a lesson that he shouldn't be selfish and treat everyone the same way you treat yourself. But, Lincoln, though, he's just annoying and basically convinces his family to move to SCOTLAND, which is pretty ridiculous. Anyway, beside those, it's still a good movie.
What about the cartoony scenes? Back in Season 4, the Loud House universe was something in real life and anything humans can do. However, in Season 5, the series just turned from a real life into a fantasy world. Anything that a human cannot do. We had many episodes that an acutal human CAN'T do and basically turned the show into some fiction.
So, for my conclusion, this film is pretty good. I wouldn't mind to rewatch it, even though it is confusing and the plot is sort of botched and the film makes references from previous episodes. It's still a good movie nonetheless. (It also takes place between Season 4 and 5)