Apologies up front, fanboys: It takes a while for Kick-Ass, the highly hyped adaptation of Mark Millar’s comic, to live up to its title. A more appropriate moniker for the film’s weaker parts might be, say, Girly Slap—if only it weren’t for the very, very young femme fatale who ultimately steals the titular hero’s thunder. Sure, it’s somewhat amusing, in a festival-precious, Napoleon Dynamite kind of way, to get acquainted with nerdy high-school student Dave Lizewski (Aaron Johnson), a gangly Harry Potter type whose only self-declared superpower is “being invisible to girls.” Dave finds it unbelievable that in this newly golden age of superheroes, no one has tried to don a cape and reinvent himself as an iconic crime-fighter. But he’s obsessed with the idea, even if, unlike Batman, Dave doesn’t have any score to settle beyond standing up to bullies when he orders a costume and haplessly tries to stop New York City bad guys as “Kick-Ass.” Not surprisingly, he’s the one who initially gets his ass kicked, once so thoroughly that he emerges from surgery with deadened nerve endings and a skeleton like Wolverine. Still, his adventures and the sarcastic support he gets from his friends (Clark Duke and Evan Peters) are more wince-inducing than thrilling, and they may leave audience members unfamiliar with Millar’s work wondering what made Layer Cake director Matthew Vaughn take on such a tepid, teen-friendly project. But then sweet-faced tween Mindy (Chloe Moretz) gets shot in the chest by her dad (Nicolas Cage), and eventually the film rockets into Quentin Tarantino territory as Mindy, aka Hit-Girl, and her father, Big Daddy, start saving Dave’s ass. Drug-dealing mobsters, whose unflinching boss (Mark Strong) is the father of Dave’s loner classmate (Christopher Mintz-Plasse), are the central baddies here. And although they are the kind of toughs that Kick-Ass couldn’t even rough up in his dreams, wee Hit-Girl is there to help—and it’s bloody fantastic. The sensitive will surely faint in horror, but there’s something incredibly thrilling about a little girl who’s always armed with throwing stars and a butterfly knife and can mow down a room full of big men with big guns. Even better? The action scenes rarely seem unrealistic, especially when Mindy’s upbringing and her father’s own vendetta are taken into account. Kick-Ass does assist Hit-Girl in the film’s final blow-out, but when the movie ends, it’s the child you’ll remember while an earlier line from Dave’s voiceover rings true: “Me? I was just a stupid dick in a wet suit.”