For the most part, it’s the story itself. While recent releases like Shark Tale, Madagascar, Robots and Chicken Little remain high in eye-candy value and are not without their own entertaining moments, they certainly don’t quite stack up with most of their first-gen counterparts, which are now considered classics by any film standard, CGI or not.

Now that’s where Ice Age: The Meltdown comes in. A sequel to the box-office hit that was not exactly endearing to most critics who found it "uneventful" for the most part, the new Ice Age gets a much-needed shot in the arm with a far better script and a more engaging storyline. Aside from the characters, what exactly do you remember about the first Ice Age anyway? I thought so, too.

Well, this one should have been what the first movie is all about. Here’s how Yahoo! Movies sums it up: "The Ice Age is coming to an end, and the animals are delighting in the melting paradise that is their new world. Manny, Sid, and Diego quickly learn that the warming climate has one major drawback: a huge glacial dam is about to break, threatening the entire valley. The only chance of survival lies at the other end of the valley. So the three heroes, along with a mammoth named Ellie and her two "brothers" — possums Crash and Eddie — embark on a mission across an increasingly dangerous landscape towards their salvation."

Now that’s more like it, huh? The end of the real Ice Age has more historical (or in this case, pre-historical) basis and I thought it was great that the movie also touched on the eventual extinction of one of the prehistoric animals represented by one of the main characters.

The more extensive development of the characters in this movie is also what sets it apart from its predecessor. Here, we no longer just "hear" the famous voices of Ray Romano (Manny), John Leguizamo (Sid), Denis Leary (Diego) and new cast member Queen Latifah (Ellie), we can actually identify them with the characters that they’re playing. And even the actors themselves find it exciting to play them in a more different light.

"I love Manny as a character, and I love playing him," says the star of the now defunct Everybody Loves Raymond. "His values and spirit are terrific. He’s a curmudgeon with a big chip on his shoulder and a tough exterior. But underneath that, he’s all warm and fuzzy — for a mammoth, at least."

"Actually, it was exciting to be in an onscreen romance," he adds. "But I had to remind myself it’s an animated film, right? Queen Latifah, who voices Ellie, wasn’t even in the same recording booth as me! As for Ellie, he gives Manny a twinkle in his eye. But, unfortunately, she’s a bit ‘off’, so it’s not smooth sailing. Though it was easy to make that work, because I was able to rely on my own lack of knowledge about talking to women."

The desire of Sid The Sloth to get more respect in Ice Age The Meltdown is something that is not lost on John Leguizamo. "There was still unfinished business left over from ‘Ice Age’ that I was eager to get into," says the actor. "I wanted to re-create that same lovable character but take him to another level."

And Denis Leary who plays Diego the sabertooth found something in the new script to play with. "Ray Romano gets the film’s emotional moments, John the funny ones, but Diego makes it all happen," says Leary. "Diego is still a leader — smart and strong, but he thinks he may be getting ‘soft’ because of his fear of the water."

The new film also benefits from the addition of Queen Latifah who plays the livewire but confused mammoth Ellie. Latifah is literally playing possum here. "Ellie is just the sweetest, lovable lump that you’ve ever seen. But she’s…well…she’s a little strange. A little aloof and, yes, a little confused about her identity. You see, Ellie thinks she’s a possum. But she’s really a woolly mammoth. That’s real confusion!

"I think one of the reasons I enjoyed working on this film was because of the innate vocal rhythm I have as a musician. You catch things off that rhythm and you hear things a bit differently. So it was interesting for me to get Ellie’s vocal inflections and make sure they worked for the character."

Of course, no Ice Age movie is complete without its resident comic relief, Scrat, who undergoes some of the biggest character-based changes. This little bugger is still chasing the nut but the filmmakers have added new dimensions to his antics. There’s one particularly hilarious scene, where he’s chased by a small army of snapping piranha. Scrat then surprises everyone, including the audience, by going into Bruce Lee mode and displaying virtuoso martial arts moves that leave the deadly fish down and out.

"Audiences tuned into Scrat right away," says Chris Wedge, the director of the original Ice Age who also voices the character, "because everyone relates to an underdog. Now that we’ve given him new dimensions for the second film, we expect an even bigger response to Scrat."

All told, while there are graphical enhancements in the overall look of the original characters and additional textures and even the higher polygon count certainly didn’t hurt in creating its equally jaw-dropping environment, what is truly worth celebrating about Ice Age The Meltdown is its much-improved story and characterization, which raises the film above the CGI mediocrity that has been unleashed one after another as of late.