This is not a perfect film at all, in fact I found it slightly dim in certain areas. Particularly, the lack of character care. To connect and actually care about the fates of the lead characters is quite an important factor. Without compassion, the legacy of the film will fade rapidly. There is a clear level of tackling done to avoid any shallowness, such as making Ward a father with a brief backstory. But that's where the development stops.
That is not the film's only downfall, with the extended action taking sole presence over quality. As I've stated above, the 148 minute runtime is noticeable. The exact same film could have been told within a 90-100 minute time frame, but it seems that horde attacks and cool fight scenes were more important than keeping the audience's attention. I'm not saying that the film is bad in any shape or form, but a sense of ruthless editing is certainly needed.
Overall, I'd describe Army of the Dead as a mix of World War Z's fast paced ferociousness, with a fair portion of Zombieland's humour and quick wit. The combined gorefest is a visual festival of vibrant colour and beaming lights, but just be prepared for a lack of deeper narrative.