In Gillian Flynn’s novel “Gone Girl,” protagonist Nick Dunne admits right away that “I have a face you want to punch.”

“I’m a working-class Irish kid trapped in the body of a total trust-fund [jerk],” says Nick, under suspicion for possibly killing his missing wife, Amy. “I smile a lot to make up for my face, but this only sometimes works.”

Enter Ben Affleck, cast as Nick in the David Fincher movie adaptation of the book (also written by Flynn), which opens in theaters Friday. On the surface, it would seem like an ideal fit. Affleck certainly has Nick’s movie star looks … seeing as he’s an actual movie star. Yet at the same time, he often appears inexplicably smug as one of Hollywood’s A-listers, even after clawing his way back to a comeback after some box-office disasters. So, this role is easy to pull off if you already have the face, right?

Only in this case, Nick’s looks actually go deeper than just a character description. That’s because Nick’s handsome features offer a window into his psychological make-up: His whole life, he’s had a deep-seated need to prove that he’s a decent guy, despite having a face that could belong to a stereotypical prep school bully. (Amy, played by Rosamund Pike, even teases him in the movie about his “villainous” chin.) Thus, he smiles at inappropriate times — i.e. standing next to a poster of his missing wife — which leads many people to believe he’s an unfeeling monster.

“He’s so hot,” one young woman whispers in the movie, staring at Nick during a vigil for Amy.

“Ew,” another responds. “He’s so creepy.”

And there’s the line that Affleck had to walk. Appear exactly good-looking enough that some people love you without questioning anything, but at the same time, be just unsettling enough that the other set of the population finds you appalling.

So, how did he do? To the surprise of some, the actor — who has made some questionable acting choices over time — excelled in this role. Pike got nearly unanimously rave reviews for playing the extremely complicated role of Amy. Still, the praise of Affleck is more notable simply because, as we’ve seen, he can be a polarizing figure. Here’s what some of the critics said about his performance:

Kevin Fallon, Daily Beast (calling it the best role of Affleck’s career): “Ben Affleck is excellent in ‘Gone Girl.’ He’s not just movie-star excellent, though, where a sly grin and chiseled-jaw charm makes an actor magnetic enough to entertain or carry a movie… He’s excellent as in, like, actor-y excellent. As in, like, we may all need to start changing our minds about how we feel about Ben Affleck, the actor. Because, based on his performance in ‘Gone Girl,’ he’s a really freaking good one.”

Scott Mendelson, Forbes: “Affleck is terrific, although frankly the role fits him to a tee.”

Ann Hornaday, The Washington Post: “Playing Nick with thick, bleary-eyed handsomeness, Affleck is quietly persuasive as a guy who in another era might have been a master of the universe, but is still reeling from having that perch snatched from under him.”

Justin Chang, Variety: “Affleck is uniquely suited to the role of a man facing those very charges from a fickle and demanding public; it’s a tricky turn, requiring a measure of careful underplaying and emotional aloofness, and he nails it completely.

David Blaustein, ABC News: “Affleck delivers what’s easily his best performance.”

Chris Vognar, Dallas Morning News: “Pike and Affleck are perfectly cast…Pike envelops herself in a constantly shifting role. Affleck, criticized in the past as too charming for his own good, plays up that quality and makes Nick both callow and sympathetic.”

Rafer Guzman, Newsday: “Affleck is perfect as the handsome, hapless Nick, while Pike is dazzling as Amy.”

Kenneth Turan, Los Angeles Times: “Affleck, who’s had his own personal deer-in-the-headlights moments, gets Nick’s combination of arrogance and likability exactly right, and Pike…is completely his equal in a performance that defies expectations at every turn.”