As much as even the fans nowadays tend to agree with the critics that the series has overstayed its welcome after each subsequent film became increasingly lacking in quality, the early warning signs for the meltdown the series' reputation would suffer were present well in advance.
- A common criticism of later sequels is that the humor became increasingly out of place, gross, and inappropriate; not to mention too bountiful to allow the films to be taken seriously. However, while the original film was considerably more serious compared to the sequels, it wasn't entirely devoid of humor itself. The difference however, is that the original film balanced out all the slapstick and snark based humor with plenty of drama and heart that granted the story a sense of sincerity while also allowing only at least one instance of each of some of the more potentially unfitting forms of humor and allowing all the humor in general to be well timed enough to feel natural and provide levity when as much was needed. Unfortunately, with each sequel released, the amount of humor present became increasingly high to the point that, by the time of the final theatrically released film Ice Age: Collision Course, all potential drama and heart to be found was almost completely buried under an avalanche worth of jokes that were at best jarring or out of placenote , and at worst annoying or redundantnote .
- A related complaint was how the series became increasingly Denser and Wackier after the original had managed to maintain a fairly realistic tone and setting (barring small cases of Misplaced Wildlife and Anachronism Stew including animals that died off long before the Pleistocene, when the ice ages would've actually occurred). However, the earliest seeds for this trend's worst excesses could be found planted in Ice Age: Dawn of the Dinosaurs, which introduced a hidden Lost World filled with Living Dinosaursnote . But many fans were entirely willing to look past this due to how the film contained a natural heartwarming conclusion to Manny's character arc and the introduction of insanely popular Breakout Character Buck—plus, of course, dinosaurs. But when Ice Age: Continental Drift and especially Ice Age: Collision Course kept on introducing even more unrealistic elements and cranking them up to increasingly cartoonish and exaggerated levelsnote , the stories became so difficult to take seriously that even the fans finally began to agree with the critics that the series had overstayed its welcome.
- Another common criticism of Ice Age: Continental Drift and Ice Age: Collision Course is the constant adding in of new characters to the main cast. But for all the hay made about this detail, the beginnings of this trend could be found as far as the comparatively better recieved Ice Age: The Meltdown and Ice Age: Dawn of the Dinosaurs. In The Meltdown, Ellie's romance with Manny takes up so much of the runtime that, between said romance and the threat of the flood, Diego's arc about overcoming his fear of water has only about 1/4 of the film's running time at best devoted to it while Sid's Dude, Where's My Respect? arc feels like a complete afterthought. But this was easier to overlook in The Meltdown since Ellie's presence made understandable narrative sense on account of how her romance with Manny felt like a natural continuation to Manny's arc from the first movie about being able to move on from the pain of his tragically lost first family and provided a happy resolution to his fears of being the Last of His Kind he'd been undergoing prior to meeting Ellie; meanwhile, all the time she got devoted to her in the narrative allowed her to be fleshed out enough to be able to stand on her own merits as a character and not come across as a Satellite Love Interest. And as comparatively underserved as their respective arcs are, Diego still managed to have the 2nd highest amount of screentime devoted to his arc after Manny while Sid made up for his own individual arc's comparative lack of focus by playing a crucial role in helping Diego face his fears. And while Crash and Eddie were hardly considered the most beloved new characters at even their introduction point, they still largely only contributed their brand of humor fairly rarely and still had their humor mitigated by how much they genuinely cared for their adoptive sister Ellie. Similarly, Dawn of the Dinosaurs introduced Buck and Peaches while having Diego's arc of feeling like he's starting to lose his edge get much less screentime compared to Manny's arc of becoming a father once more and Sid's arc of trying to be a parent to the trio of baby T. rex. But Buck was fleshed out enough as an equal parts crazy and badass adventurer to become a popular character in his own right, and was also written out of the story at the end by choosing to ultimately stay in the Lost World so that he wouldn't risk overstaying his welcome in the narrative. Peaches, meanwhile, wasn't introduced until her birth fairly close to the end of the story, and largely served as more of a living prop than an actual character with her own arc due to only being a fairly newly born baby at that point. And much like how Sid played a crucial role in Diego's arc from The Meltdown, Diego similarly made up for his own arc's comparative underserving in Dawn of the Dinosaurs by playing a key role in Manny and Ellie's shared arc. But by the time Diego's formerly evil Pirate love interest Shira, Sid's Granny dumped on him by his uncaring familynote , Peaches' hapless fiancée Julian,note and Sid's passionate new girlfriend Brooke got introduced to the fold, alongside bringing back Buck and having him stick around again, the cast had become so massively overcrowded that not only did the brand new characters get nowhere near enough time to get properly fleshed out enough to allow fans to like them on their own merits, but many of the characters that had come before them get increasingly pushed to the wayside or flanderized to the point that even they started to become increasingly difficult to continue rooting for and getting invested in. The Ice Age Adventures of Buck Wild seemed to get the idea and pushed out all main characters that weren't Manny, Sid, Diego, Ellie, Crash, Eddie, or Buck.
- Later installments got criticized for turning the franchise from a semi-accurate portrayal of animals surving the Ice Age into a Fantasy Kitchen Sink with dinosaurs and fantasy elements. However, it can be argued that the trend started with Cretaceous and Maelstrom, who are reptiles from the Mesozoic era that were long extinct by the time the Ice Age started. The main difference is that, first of all, they do have a semi-realistic justification in the plot, by being sealed in the ice and then realesed with the titular meltdown, meaning that the creators were lampshading the fact they wouldn't be alive during the Ice Age with these two being a notable exception. And most importantly, they don't drive attention away from ice age-related natural disasters like the main flood, which is still the focus of the plot. In the latter movies, the more historically inaccurate and fantastical elements took center stage in the plot, leading the Ice Age-elements to become irrelevant, and they never bothered to give them any sort of handwave to the more jarring elements.
