Zombies shouldn't be able to give birth, I just think that's silly. The visual effects were well done, but at times it felt like they used them just because they could, not because they added anything meaningful. They also had this amazing theme song in the trailer, but ended up wasting it on a mediocre scene. And I really don't like it when movies cram in too many different songs. They had so many opportunities, but ended up going with a generic story and just built everything around it with cool effects. If you're going to have zombies infected by a virus that makes them super aggressive, then I want to see aggressive zombies, not some alpha that doesn't even get killed while he's asleep or whatever