Ender’s Game is a hard movie to peg. For the first two thirds of its running time it plays like a cross between The Hunger Games and Harry Potter, complete with its own version of quidditch and some good old fashioned kid on kid violence. And that’s fine. I love both of those franchises. But they have a decidedly teenage audience in mind.

Then all of a sudden the film flips a switch and before you know it all of the weird, airy elements of the first two acts start to coalesce into something very, very smart. It may take a while for it to make its point, but when it does Ender’s Game ends up being some remarkably good science fiction.

In the near future, Earth is attacked by an alien race known as the Formics. Mankind wins the war, but are nearly wiped out in the process. To prepare for the ever present threat of a second attack Earth begins to train children from a young age in the strategies of war, in hopes that one day they can lead Earth’s fleet against the Formics. Yeah, it didn’t make much sense to me either…

But that’s where a young boy named Ender Wiggin (Asa Butterfield) comes in. Having trained all his life in a war academy on Earth he’s handpicked by Colonel Graff (Harisson Ford)—the man responsible for finding Earth’s saviour—to attend Battle School, located on an elaborate space station in Earth’s orbit.

Now while I’m well aware the Ender’s Game books originated long before the Harry Potter series, if that doesn’t sound like the Hogwarts School of Space War to you then I don’t think you’re paying enough attention. Hollywood loves to try to emulate success, and I think it’s clear why all of a sudden the Ender’s Game story became a movie that needed to be made.

So in the early going the movie plays out much like Harry discovering the ins and outs of Wizarding School. This has its moments—mainly as we watch young Ender prove his leadership capabilities and win over his classmates—but at times it can also be quite tedious.

For the first two acts, the only reason Harrison Ford’s character seems to exist is to look on in awe of Ender’s abilities. And while there are many inventive challenges and rousing triumphs in Battle School that will make you want to cheer, many of the tactical games that comprise it just seem to boil down to a bunch of scientific mumbo jumbo.

Perhaps my biggest complaint is that everything—every relationship formed or broken, every bully dispatched—seems to devolve into long discussions of strategy, which can take some of the humanity out of the characters. That’s partly by design. We’re supposed to be able to see the conditioning these kids are put under, not to mention the type of thinking that makes Ender so special. But it’s somewhat overdone, and because of that many of the emotional beats in the movie come off as insincere.

That is, of course, until the aforementioned third act. For all the problems I had with the first two acts of Ender’s Game, the film’s finale was remarkably effective. Sure, Ender and his team can come across a little Mighty Morphin Power Rangers with their enthusiastic energy, but the themes brought forth in that final half hour or so make what came before it seem smarter just by association. Even the basic premise of using children to command armies (just writing it is enough to make me want to roll my eyes) seemed a lot more plausible by film’s end.

But more than that, Ender’s Game’s conclusion is where the movie finds its emotional resonance. You can debate whether or not it was too little, too late, but it’s hard to deny the poignancy of the film’s final few twists of fate.

If you can get past the distracting politics of the book’s original author Orson Scott Card (none of which really makes it into the film), Ender’s Game is a surprisingly intelligent, albeit uneven, story chalked full of some of the best young talent Hollywood has to offer.