The lack of blood and gore....
It neutered this movie.
I liked WWZ a lot. And I get it, they needed to keep it at PG13 in order to get a bigger audience. And sure, it was plenty fun and thrilling a ride as it was. But think how much better and scarier it could have been had we actually seen AT LEAST A LITTLE of the kind of savagery the zombies were trying to inflict on the living. We saw NONE of that. Every time you think you might get a glimpse of an attack, it gets blurred, fast-tracked to the next image. Glossed over. And every attack is a GROUP attack...a frenetic, blurry, amped-up, OVERLY fast CGI-fest.......so quick and blurry you can't really zero-in and focus on any one attack or incident.
It's a mistake not to have slowed things down a little once in a while....and shown some of the savagery....and blood. How do you have a zombie flick without those elements??
WWZ was fun....but it could (and should) have been a lot better.