It is a truth universally acknowledged that a single animated film in possession of a good box office must be in want of a sequel. So while the feelings of views of such audiences as watched Happy Feet may be, they will be getting Happy Feet 2 whether they needed it or not.
I think we can all agree that Happy Feet ended on a fairly closed note. Mumble became accepted by his penguin colony, taught them to dance, found love, restored the fish supply, and overthrew centuries of oppressive penguin religion. What more is there to tell?
I can't say I know the answer to that – Does humanity overfish again? Probably! -- but there's one lingering thought I've got: Why the hell does Mumble still look like a baby penguin? And how, if his growth stunted, was he able to sexually reproduce?
I know, that latter question is getting a little too biological for a kid's film. But come on, Mumble just looks creepy with his pseudo-baby feathers, especially when he's a father of his own adorable chick.
According to Wikipedia, Mumble is stuck permanently in his baby feathers because of being dropped by Memphis as an egg. I'm not sure that's supported by the film, which makes a point of implying that baby feathers are shed once the penguin meets the requirements for sexual maturity, which was singing one's heartsong. Because Mumble proved dancing was just as good as a heartsong, he should have been able to "graduate" and get rid of his feathers too. In fact, there's a hint that he does because a little feather drifts out of the screen in the final scene.
But in Happy Feet 2, Mumble is still in baby feathers. This is biologically impossible. The downy feathers of a baby penguin aren't up to the rigors of cold weather and water that adult penguin feathers are. That's why they're so dependent on their parents for survival. Mumble wouldn't be able to survive the harsh conditions of Antarctica half-covered in baby down, especially since he has to take the trek to the water to feed himself after roosting with his egg. He'd freeze, and the chick would freeze, and there would be no Happy Feet 2!
And those blue eyes! Surely they're not appropriate for the ice-glare of Antarctica. Light colored eyes are more prone to photophobia (a fancy word for light sensitivity, see how much research went into this?) which is why I assume all penguins (and the majority of animals in general) have dark eyes. They don't exactly have access to Ray-Bans. Is Mumble going to go blind? Will his blue-eyed chick?
Someone out there will argue that Mumble had to keep his odd appearance because of children needing to make the visual connection. But the first Happy Feet came out in 2006. Any kid who saw it then, even at 2 or 3, is old enough to recognize Mumble's name and voice if he looks like an adult penguin. For kids new to the "franchise," it wouldn't matter at all. The focus is going to be on the adorable baby penguin, Erik, so what difference would it have made to be accurate to nature? (And let's not underestimate kids – they can accept the natural progression of time and characters easier than we think!)
Is Mumble some kind of new species of penguin, a mutant spawned by the genes of Hugh Jackman (no surprise Wolverine would produce a genetic aberration) and Nicole Kidman? Will little Erik suffer the same deformity? Will his off-spring? And theirs? What happens when these traits are spread through the penguin colony? Did Mumble save his species, only to doom it to a genetic mutation that ensures all penguins experience a short life of an animal ill-suited to Antarctica's harsh climate?
This is the question I need answered in Happy Feet 2. And maybe just how they all knew all those pop songs. I mean, really. Where are the penguin songs?