The Denser and Wackier approach to the series has seemingly reached its peak with the Shangri-Llama, a supposedly mystical shaman who will save the Earth from the asteroid. Is he a funny addition to the series or a stupid character already?
Julian, by one hand he's seen as an unnecesary addition to a franchise that has already being critized for having too many characters and his subplot with Manny and Peaches is very disliked, by the other hand he's one of the few characters of who you can legitimate root for and is shown to be a legitimate Nice Guy in comparison to the rest of the Herd in this movie.
Broken Base: Any movie series will have one by the time it reaches its fifth installment, so it's expected for there to be some divisiveness.
Whether ending the series here is a good idea or not; while some die-hard fans may want the series to continue, especially due to this film's less-than-stellar quality being considered a disappointing end to the series, others wish that the 14-year-old franchise with increasingly negative reception be put out to pasture.
Darkness-Induced Audience Apathy: Despite Scrat's scenes still being regarded as the highlight of the film, many are losing interest fast since it seems Scrat's purpose is only to cause catastrophe and constantly fail to get his acorn.
It's the Same, Now It Sucks!: One of the chief complaints against the movie is that it's unoriginal and not creative at all, and several critics contended that it felt more like a Direct-to-Video film. Manny's domestic issues in particular are criticized for feeling like standard sitcom drama.
That, however, is a turd. Explanation There's a scene where Crash and Eddy lick what is supposedly a rock after seeing Buck do so earlier (as a stand-in for relative age dating), then Buck says this line. Replace the rock with a good installment of a series or a good piece of media, and the turd with a bad one, and you have this meme in a nutshell.
"That's the stupidest thing I've ever heard!'' Explanation A line uttered by Neil deBuck Weasel upon hearing the raptors' scheme to avoid the asteroid. Used as a response to stupid comments or ideas on forums or social media.
Sequelitis: Collision Course is nowhere near the quality of any of the previous films, according to the critics. The idea of it being an unnecessary sequel is a prevailing theme in many reviews. The film holds the lowest critical score on Rotten Tomatoes (16%), not just for the series, but for Blue Sky Studios as a whole. It was also far less successful at the box office than its predecessors (though still managed to be profitable). An interview indicates they have plans for a sixth film, but said interview also took place before the film tanked.
Shira went from being a major supporting character in the fourth film to an extremely minor character here. She has a minor subplot in which she and Diego are discussing having children and wanting to gain acceptance from the other members of the herd, and a brief scene at climax where she and Diego are Manny's right-hand-men, but she's barely in the movie. Several people questioned why they even bothered hiring Jennifer Lopez to reprise her role that had barely any lines this time around.
Fans were disappointed that Louis, who was also a major supporting character in the fourth film, only got a mere, silent cameo here. To be fair though, they probably couldn't get Josh Gad back to reprise his role.
Some feel that since this film was hyped up to implicitly be the Grand Finale, they should've brought back characters from previous films like Roshan, Carl and Frank, and the remaining pack of sabers from the first movie, Fast Tony and Cholly from the second, Scratte, the T. rex family and Rudy from the third, or the surviving pirates from the fourth for a major case of Back for the Finale. Even more disappointing is the fact that this may never happen at all, due to this film's negative reception and low box office draws icing any chance of a sixth film.
The Dino-bird villains get some flack for not being as interesting as the previous films villains since their plan to prevent the heroes from stopping the asteroid is utterly illogical and they constantly fail at every opportunity. One of the things that makes them stand out is that they are the first and possibly only villains who redeem themselves at the films end.