No one watches a gory, action-packed zombie flick for its emotional range, but “Army of the Dead” has about as much heart and wit as its undead antagonists.

The big-budget movie, which was released in theaters May 14 and on Netflix last Friday, is the latest from director Zack Snyder. His 2021 film “Zack Snyder’s Justice League” — his preferred cut of the original 2017 “Justice League” — received praise from fans and critics and clocked in at just over four hours. While “Army of the Dead” doesn’t even come close in length, its sizable two and a half hours succeed in terms of action, but fail to develop the film’s extensive cast of characters.

The film takes place in a post-apocalyptic Las Vegas, where the United States has trapped its population of zombies in order to prevent further spread. Scott Ward (Dave Bautista) was an expert zombie killer during the initial outbreak, but now works as a fry cook at a rural Nevada diner. Scott finds his peaceful life interrupted when Bly Tanaka (Hiroyuki Sanada), a casino owner, offers him $50 million to enter his casino in the quarantined city, crack the safe and retrieve the cash.

Scott immediately agrees, and puts together a team of friends from the early days of the apocalypse, alongside new faces such as Ludwig Dieter (Matthias Schweighöfer), a naїve German lock breaker, and Mikey Guzman (Raúl Castillo), who has gained social media fame by livestreaming his zombie kills.

In total, 11 characters join the team to enter the city. As is to be expected from any zombie flick, not every character is important, and someone has to die first — and second, and third. Still, the film takes the entire first hour to introduce every character, without giving any backstory to anyone besides Scott, his daughter and his closest friends — Vanderohe (Omari Hardwick) and Maria (Ana de la Reguera).

As a result of the large cast, few characters reveal any motivation for their part in the mission beyond the ample payment promised. That fact makes them difficult to root for at times, and even the lead protagonists can read as a little shallow.

We know that Scott wants the money to win back his estranged daughter, Kate (Ella Purnell), and help her evacuate the refugee camps on the outskirts of Vegas. Dieter, too, has a motivation beyond money — namely, the thrill of breaking into one of the most armored safes in the world.

Without spoiling the ending, the team’s struggles could read as divine punishment for their blind greed and hubris. Scott and his friends are seasoned veterans of the apocalypse who have killed countless zombies, but the mission proves more than they bargained for — the team apparently knows less about the undead roaming the city than they initially thought.

Snyder adds layers to the zombie lore of “Army of the Dead” which make its creatures far scarier than the slow, blundering corpses of “The Walking Dead” or “Night of the Living Dead.” Las Vegas is, in fact, full of slow zombies, but those constitute the lowest ranks of the undead hierarchy. The original zombie has become the leader of the hordes of the undead, and he and his compatriots are remarkably fast, strong and deadly.

The presence of these “elite” zombies proves one of the most interesting aspects of the movie. They seem to communicate with each other, hold quasi-religious rituals and even form social attachments to one another. Their near-humanness makes them an unsettling and worthy foe.

The audience is left to question, though, why Scott and his team, who have apparently spent extensive time in apocalyptic Las Vegas, seem unaware of the fast zombies. One would think that they would be familiar with both types of undead, especially since immediately upon their arrival inside the borders of the city, they encounter two of the fast zombies.

The fast zombie problem is one of many dizzying plot points in “Army of the Dead.” On top of that, Scott’s team must complete their mission before the U.S. government obliterates all of Las Vegas in an attempt to end the zombie problem.

Meanwhile, Kate only accompanies her dad on the mission to find her friend, Geeta, who had entered the city to loot the abandoned slot machines and never returned. The massive cast and multi-layered plot are a lot to keep up with, especially for a movie that promises mindless explosions and gore.

“Army of the Dead” certainly delivers on those promises, though, with moments of real nail-biting suspense, including a scene in which the team must navigate through a sea of hibernating zombies without awakening them. The practical effects are delightful, too, with impressive stunt work and zombie makeup that holds up in HD. Perhaps the most fun to watch is a disembodied zombie head, achieved through animatronics, which continues snarling and moving its eyes without use of its body.

The skilled practical effects in “Army of the Dead” add to the quality of the film, and bad practical effects are oftentimes better than middle-of-the-road CGI, which unfortunately also makes an appearance in the movie. A zombified, CGI tiger guards the boundaries of Las Vegas, warding off human scavengers while also proving that just because you can do something in CGI doesn’t mean you should.

Despite plot holes, one-dimensional characters and disappointing CGI, “Army of the Dead” is good, mindless, post-apocalyptic fun. Reducing the size of the cast to allow the audience to form deeper connections to the characters could give the movie what it’s missing — a reason to root for each of the colorful protagonists.