Murali posted a review for Zombie Army 4: Dead War in Games

It may feel overall familiar, but Zombie Army 4 does manage to separate itself from the already sizable horde of cooperative zombie shooters in a few enjoyable ways. For starters, the story is delightfully absurd, with occult forces bringing the Nazi army back from the dead, seemingly from the literal bowels of Hell. Its roughly eight-hour campaign ends with a ridiculous and surprising final confrontation that is worth seeing unspoiled. A simplified Horde mode exists as well, if you just want to stick to one location and see how many waves you can take on while experimenting with different weapons. I prefer the variety and forward momentum of playing the full campaign, but Horde offers plenty of opportunity for intense shootouts and last-second victories