If one were to compare the plot of this film to another, it most resembles the innocent encroachment theme in Dances with Wolves and “the strong taking from the weak” theme in Avatar.
Humans need land to prosper and grown and that need sometimes overpowers compassion and compromise. This is a common theme in human history. In Battle for Terra, the theme is not one of a society growing beyond its means, its one of species survival. That need clouds judgment, makes choosing courses of action that would otherwise seem irrational, sane. Hard decisions are made. Battle for Terra gives both sides of the argument but neither version nor ideology is skewed in favor of one or the other. In end, both want peace but are willing to pay for and ensure it differently.
The fact that the mostly civilian Terrians beat human soldiers trained since they were eight years old is highly implausible, especially since the film adheres to reality so astringently but costless live action films egregiously falter in similar regards all the time.
Family moments are especially well done in Battle for Terra, as it is a prime motivator throughout the film. There is strong voice acting by veteran actors throughout and dramatic moments are carried off flawlessly. The film even dabbles in our childish notion of large eyed aliens.
The computer animation in Battle for Terra is top notch, but not the highest, not what the viewer would find in current Pixar or Miyazaki films. The beginning animation scene is like Star Trek: Voyager’s, where an Odysseus captained spaceship sails lonely through an outer space that would conjure in any Carl Sagan-aspiring astronomer poetic delight. The viewer will be surprised at it quality and in how much work was put into Battle for Terra to make it a real film, beyond the boundaries of animation, and create real cinematic moments. As repetitious a concept as it very well is, not learning from the past and repeating those mistakes, is the mawing, lubed trap that the desperate humans in the film fall into , even after completely destroying three worlds. Their barbarism goes so far as to abduct, dissect, and kill sentient, cognitive beings just to learn more about them. God forbid the humans peacefully introduced themselves, struck an amicable accord, and passively examined the Terrians’ physiology.
And lets not forget the obvious: The humans in the film live in an air enclosure in outer space. Why not create an enclosure or a series of similar enclosures on Terra? This should have dawned on someone onboard that ship, especially Jim Stanton (Luke Wilson) after he was saved by a small scale one created by Mala (Evan Rachel Wood) on Terra. Also, why terraform the entire planet before even searching it for oxygen producing plants?
On the opposite side of the equation, themselves no strangers to a warfare-bearing past, the Terrians resolve themselves to violence in defense of themselves and their home, an ironic choice since that resistance is manipulated by the human powers-that-be into a quasi-justification for direct military action against them.
Aristomenis Tsirbas’ Battle for Terra is far more of an impressive, mature film than some would believe because it is animated and therefore written off or seen as a shortcoming. This is an oversight on their part. Battle for Terra is a good piece of sci-fi film making.