Little more than a month after DreamWorks' fledgling 3-D adventure Monsters vs. Aliens arrives in theaters, Lionsgate produces Battle for Terra, its own unofficial sequel, also in 3-D but with us playing the monsters this time. A predictably heavy-handed message film gussied up with special effects and action sequences that almost overcome its message and its predictability, Battle for Terra is a much better film than it has any right to be, and it should be good alternative programming for both adults and kids when Wolverine is sold out this weekend.

Evan Rachel Wood (The Wrestler) plays Mala, a restless, tadpole-shaped creature who regularly defies her exasperated father, Roven (Dennis Quaid), and cowardly pal Senn (Justin Long) in order to satisfy her impulse to explore. Her inventiveness and dexterity are soon put to the test when members of her peace-loving community are abducted by mysterious creatures from the sky and Mala manages to crash one of their vessels on her planet.

After she rescues its pilot, a human named Jim (Luke Wilson), Mala strikes up a tenuous friendship, only to discover that he is merely an envoy for Gen. Hemmer (Brian Cox), who plans to conquer her planet and recycle its atmosphere for human inhabitance, in the process killing all of Terra's indigenous life. Informing Terra's elders of Hemmer's plan, Mala finds herself at the center of a battle for the future of the planet when the humans attack and the peace-loving Terrians are forced to revisit their war-torn past in order to protect themselves.

While it's initially difficult to take seriously these generic, crudely animated creatures, which look like little, floating spermatozoa, it's also surprising how affecting Battle for Terra eventually becomes. Though it's by no means a masterpiece, its energy and its execution recall the best of the Star Wars prequels in terms of manufacturing a mythology, not to mention its frenzied, thrilling battle scenes. Truth be told, it recalls a virtually bygone era in movie-making that seems to no longer exist, where filmmakers create a (literal) universe from scratch, populate it with unknown and mysterious creatures and then use that as a backdrop to tell a compelling story.

At the same time, anyone looking for a subtle message or metaphor will be disappointed by this film's clunky moralizing, which registers about as tenderly and discreetly as an anvil to the skull. While the rest of the characters look fairly nondescript, Gen. Hemmer is the spitting image of George W. Bush, and the character's philosophy—that the military, not the politicians, should make policy—leaves no room for ambiguity when the time comes to figure out what the movie is saying. That said, the peaceful Terrians could serve as stand-ins for any oppressed group, particularly including nature itself, but Battle for Terra wastes no time getting straight to the point when the time comes to point fingers and teach lessons.

Ultimately, however, I was surprised how much I enjoyed the film, because of both its action scenes and the fact that it assembles an interesting new world that isn't unique, necessarily, but hasn't been seen before. In other words, Battle for Terra isn't all great, but it knows what it is and knows what it's doing. And as someone wisely observed, knowing is half the battle—which, thankfully, in this case is more than enough to win your interest.