Army of the dead begins as though it's going to be a fun B movie. 2 exchanges in different vehicles leads to disaster which leads to terror which leads to a fun title sequence in which we see a garish Las Vegas overrun by Zombies. This title sequence packs in a lot of story; in fact, in packs in about 90% of the movie's story.
After that a bunch of people decide to go into Zombie-infested Vegas to get some loose cash, which is what the rest of the movie is. In spite of the absence of story, there's still a long chunk of time between the credits and the action which is filled with the strikingly dull enlisting of cannon fodder.
You might have a few questions as the movie begins. Are the protagonists being mislead by the billionaire who puts this in place? Is the soldier they're forced to take along untrustworthy? Will someone sacrifice themselves for others even though they probably could have saved themselves as well? Will someone risk everyone's lives on a side mission? Will things suddenly become way more urgent? Will the characters be too undeveloped for you to care about them or their mission? Will this all result because no one in the movie even considered the possibility that things weren't what they seem? Will you be unsurprised at the "surprise" ending?
If you don't know the answer to any of these questions then you've never seen a movie before and might like this one. Otherwise...
There's little attempt to bring these characters to life except in several tediously emotional conversations between two characters you don't care about.
Yes, there are some good moments here and there. The aforementioned opening credits. Zombie animals. A quiet scene with an unquiet finale. Occasional moments of good action or suspense. But it all gets suffocated by the length, the slack moments, the predictability, the stupidity, and the high "who cares" quotient.
Zack Snyder is a hit or miss director, but normally his failures are from pretension and hubris. This time he didn't fail because he was too ambitious, but because he seemingly had no ambitions at all.
