The main character is an unlikeable teenager with too much attitude. The plot of the film is not very interesting: when non-human animals die, they go to heaven, but some can't find the way, the so called "secret pass", so some "chosen ones" (shape-shifting humans) have to help them. Why do humans think they are so much more important than all other species that they have to play a central role even at the time of death? The premise is just dumb.
The film plays like the "lost animals" are still alive (they fear dying, but they fail the basic instinct of fleeing from humans, most of them actually trusting the "chosen ones" without a hint of hesitation or whatever, even when they are picked up by their alter egos, which are huge birds of prey). The metaphor is too obvious, but it's slapped on the viewer's face at the end, when one of the animals hears the voice of its deceased "wife" calling from beyond the "secret pass". It tries too hard to be smart, ending up looking very dumb.
There are no explanation for the whole family being shape-shifters. It tries to credit it on some kind of holy spirit's gift, but it also tries to make it sound like the "chosen one" has to be able to change by itself. "Magical" isn't an excuse to be "illogical".
The story is very boring, filled with forced thrills (that are not thrilling, just silly) and some very irking moments of total lack of reason, with the rules of the magic changing all the time.
The ending is obvious, fully happy, of course, with the villain's demise caused by himself, in a twist that is not a twist, because one of the characters gives out the outcome way before that: to open the secret pass, one has to sing a song exactly, and only the chosen one is told the correct song by the holy spirit, so when coerced, the protagonist sings the wrong words to the villain, so when he tries to open the pass, he's disintegrated...
Of course, "happy ending" is a point of view, as it's made very clear that all non-human animals die or are already dead when they go through the secret pass.
Worth watching? Forget the voice talents behind it, they do as well as can be done with such a messy plot, so, pass...