Henry Cavill as Superman in ‘Man of Steel.’ (Photo courtesy Warner Bros.)

In a 21st-century dominated by multi-dimensional heroes like Batman and Iron Man, the Superman franchise conjures up feelings of all-American nostalgia more than anything. Zack Snyder, director of “Man of Steel,” attempts to depart from this in his summer blockbuster, but does not replace it with anything more substantial leaving us essentially with another explosion extravaganza but little else.

Henry Cavill is a promising actor, but his performance as the extra-terrestrial from Krypton is not for one second believable. Cavill seems most comfortable during the beginning of the film, which due to production by Christopher Nolan (who also did the “Batman” franchise), is a lengthy and morose sequence of fragmented scenes that document Clark Kent’s self-discovery. Nolan’s influence makes Superman’s clearly demarcated sense of good and evil feel unnatural and all too simple.

Cavill brings too much rugged sex appeal to the role, making him more reminiscent of Hugh Jackman’s portrayal of Wolverine in “X-Men” than of someone who would wear a red cape in all seriousness.

It’s a tough role to pull off — while Brandon Routh in 2006’s “Superman Returns” arguably captured the role better with his more innocent approach, it clearly wasn’t strong enough to have led to a successful franchise. Cavill is intriguing, dynamic and has undeniable charisma, yet it feels like he’s holding back as the script gives him little to work with in terms of characterization or complexity. While Cavill’s performance leaves some things to be desired, he isn’t ultimately to blame for the film’s shortcomings.

“Man of Steel” opens with a home-birth on Krypton as the planet is self-destructing. Russell Crowe goes through the motions as Jor-El, baby Kal-El’s father, who rockets his son to Kansas to preserve his race. General Zod (Michael Shannon) is introduced as the film’s forgettable villain as he attempts to steal Krypton’s Codex — a log of the planet’s genetic information — from Kal-El, which remains a theme for the entirety of the movie as Zod threatens to reconfigure earth into a new Krypton at humanity’s expense.

Unfortunately, the dialogue in “Man of Steel” is as melodramatic and bland on earth as it is on Krypton. (The film’s writer, David S. Goyer, clearly is not afraid of clichés.) For the first hour, scenes jump from school buses and cornfields in Kansas to Arctic tundra with little context given, and some sort of loud catastrophe quickly interrupts any conversation that seems like it will reveal something about the characters.

Diane Lane and Kevin Costner do a perfectly satisfactory job as Clark Kent’s adoptive parents. Amy Adams, however, never seems invested in her role as reporter and love interest, Lois Lane. Adams practically sleepwalks through life or death scenes, and her kiss with Clark Kent toward the end of the movie is awkward and forced. It’s not that Adams and Cavill lack the ability to portray a believable romance; they simply do not have the script to do so, even though “Man of Steel” is an origins story that should make the audience feel attached to its characters.

The majority of the film feels like a confusing dream of drawn-out action scenes. It becomes all too easy to forget who is fighting whom, and for what reason, as Cavill darts through the air. “Man of Steel’s” shining moments are the interspersed scenes of Superman’s childhood, with a young Clark Kent played by Dylan Sprayberry and Cooper Timberline. Both actors do a fine job capturing Kent’s teen angst, sense of alienation and repressed desire to use his powers for good in a world that would not accept him.

Even though “Man of Steel” is a long 143 minutes, it goes by quickly, perhaps due to Hans Zimmer’s overpowering score and the confusion caused by Snyder’s non-linear plot. In the film’s defense, it’s difficult to create a Superman story that appeals to contemporary America. Superman’s unwavering sense of right and wrong fit so well during the Cold War, but now his narrative seems naive with more widespread recognition of the country’s internal issues and fear that its global supremacy is waning.

“Man of Steel” ends with the promise of a sequel as Cavill puts on Clark Kent’s endearingly nerdy glasses. Perhaps without the need to jumble together a creation story, it’s more likely Snyder will pull off a sequel should this chapter’s box office take justify it.