Remember the tagline for "Superman": "You'll believe a man can fly!"

For more than 30 years, it has served as maybe the most-appropriate superhero movie motto. Until now, that is, with "Kick-Ass," director Matthew Vaughn's hilariously profane, ultra-violent take on the not-quite-so-superheroes from Mark Millar's comics:

"I can't fly. But I can kick your ass." That's about the size of it, as sad sack Dave Lizewski (Aaron Johnson) tries to realize his dream of being a masked crime fighter. While not all of the elements fit together tonally, on the surface level — the level that the title suggests — "Kick-Ass" does exactly what it's supposed to, as long as you're game for the language and the gutting.

Dave is your typical comic-book nerd, yet he doesn't let his lack of physical strength or speed or anything else one typically looks for in a hero stop him from buying a wet suit and trying to stop a crime as Kick-Ass. This goes poorly, as in, land-in-the-hospital poorly.

His limited success — basically getting beaten up but taking it well, then having cell phone footage of the fight uploaded to YouTube — causes him to wildly overstep his bounds, landing him in so far over his head that his death appears certain.

Enter Hit-Girl (Chloe Moretz), as comfortable with a wide variety of weapons as she is dropping profanities as if she were a junior-sized longshoreman. And she is deadly.

Not just comic-book-style deadly, either. The violence in "Kick-Ass" is brutal, and the language would make Quentin Tarantino blush. (Moretz in particular lets loose with a word you don't hear many 13-year-old girls utter.)

And yet, in context, it makes sense. Mindy Macready, Hit-Girl's alter ego, is being raised by her father, Damon (Nicolas Cage), a former cop who ran afoul of mob boss Frank D'Amico (Mark Strong), which ruined his life and career, leaving him a single parent. Now Damon is obsessively devoted to revenge and has indoctrinated Mindy into his plan. She gets as excited at the thought of a new automatic weapon as most girls do at the notion of a new kitten.

It's a twisted look at a fascinating subject: The length parents will go to impose their own values and desires upon their children — and with those beliefs, the attendant problems. And yet it's an odd fit with the comic-book sensibilities in the rest of "Kick-Ass," as well as the funny bits between Dave and his friends, including the suddenly ubiquitous Clark Duke.

The overall tone is, in fact, somewhat hit and miss. How seriously do we take the violence, so outlandish that it comes back around to the absurd?

There's no question who we're rooting for here; that's not an issue.

Or is it? Damon dresses as Big Daddy, enough of a Batman knock-off you wonder how the film escaped a lawsuit. He leads Hit-Girl into incredibly dangerous situations — situations that he has trained her for with excruciating effort (especially for her). She loves it — it's a way for her to bond with her father, after all. But adults recognize how wrong and how misguided that bonding is. We want Kick-Ass and Hit-Girl to succeed, certainly, but at what cost?

On the other hand, "Kick-Ass" lives up to its name. The action is insanely entertaining, and the comedy at times hilarious.

Dave befriends Chris D'Amico (Christopher Mintz-Plasse), the mobster's son. Only not really — actually, Kick-Ass befriends Red Mist, the superhero identity Chris has established as part of a larger scheme. Thus, their friendship is based on, if not a lie, then something less than the truth.

And yet in any super hero movie, questions of identity are always going to be an integral part of the story.

Perhaps this is overthinking the movie and what it's trying to do.

While there are some interesting psychological and social things going on here — note that Kick-Ass is nobody until he's immortalized on YouTube — it's also perfectly content to be an insanely violent, funny take on an established genre.