There are some things that this game has going for it, such as a decent weapon selection, decent graphics, and the very satisfying X-ray kill cam. But there is one very, very, VERY big problem with Nazi Zombie Army: this has to be one of the most repetitive games I've ever played. The entire game, beginning to end, consists of the same objective over and over again:
Kill some zombies, move to a new area, kill some zombies, move to a new area, kill some zombies, move to a new area, kill some zombies, then get to the safe room. Repeat.
That's it. That's the entire game. Even the handful of boss battles in the game are all identical. Nazi Zombie Army suffers from a severe lack of variation, to the point where I felt like quitting several times, simply because of the mind-numbing sameness of all the missions. The game will sometimes try to make things more interesting by requiring you to fetch various objects in order to progress through the game, but this quickly starts to feel like a chore.
Nazi Zombie Army is much more enjoyable when played with friends, but even then, there is still a feeling of sameness that permeates the whole experience.
Do not play Nazi Zombie Army, as it becomes very boring very fast. Do not bother with the sequel either; it's nothing but more of the same repetitive, mediocre trite.