Rebellion returns to its undead Sniper Elite spinoff series, Zombie Army, for the fourth time, and while it retains the relative simplicity of its co-op shooter roots, this is the most fleshed out iteration to date. Is that enough to sustain a lengthier campaign though?

The story that started towards the end of World War II, with a near-defeated Hitler turning the tables on the Allied forces by unleashing a zombie plague across Europe shouldn’t have much in the way of legs to make four whole games about it, especially as Hitler has been sent to Hell at this stage, but credit to Rebellion, it has found ways to delve deeper into the occult-themed invasion of the dead by tapping into the ‘80s horror vibe of films by Lamberto Bava and Lucio Fulci. Complete with all the splattery, grisly, synth-backed gore you might expect of such things.

As mentioned, Hitler is defeated, but the undead plague continues to grow in number and ferocity. As such a set of war-wizened Allied heroes must set out across Europe, fending off increasingly insane types of walking corpses as they uncover the mystery behind the ongoing infection of the continent.

Much as with previous entries, the objective of Zombie Army 4 is simple, and somewhat repetitive. In each location, you must complete tasks and defend important items as you progress towards a climactic siege against a seemingly unending horde of the undead. All the while you’re fighting off smaller pockets of Nazi zombies, often with a signature sniper rifle shot. This could have made fatigue an issue, given how many times that’s been done now, but Zombie Army 4 has a few new tricks and changes to refresh its tried and trusted formula.

This new story trip takes the player to haunts largely familiar to fans of the Sniper Elite series, albeit in a darker, moodier fashion. Starting in Italy, with trips to Sardinia and Venice among the locations, and jumping to Croatia and beyond. This time around each area is split into four sprawling war-torn playgrounds per chapter. There’s no denying there’s far more room for exploration and strategy in Zombie Army 4 thanks to much bigger, more detailed maps.

Each is full of alternate pathways, secret areas, and Easter Eggs. It’s almost always rewarding to stray off the beaten path, whether it be the acquiring of a handy gun add-on, some extra grenades, or the increasingly essential upgrade points. Best of all is picking out one of the many homages to horror movies and shows. It was fun to find nods to things such as Evil Dead, and Stranger Things, as well as the more nondescript presence of multiple evil dolls spanning the entire campaign. It’s nice to have a bit more to seek out than another ripe zombie melon to explode.

All the same, combat is the meat of Zombie Army 4, and this meat is tasty. Core to everything good about the Zombie Army series are those gratuitous X-ray kill cams from a well-placed sniper rifle round.

As with its Sniper Elite origins, Zombie Army makes a gory, grisly mini-party of popping heads, shattering bones, and vaporizing more delicate parts of the anatomy. For a horror fan, it’s an endlessly fascinating (and satisfying) spectacle. The slow start to a stage allowing you to casually pick off undead from a distance, the precise strike during the chaos of a horde descending on your position, and picking off those last stragglers in an intense standoff all make for exciting repeat experiences among the exploration and panic-inducing sieges.

The art of the siege is another strong suit of the game. It’s often clear when you’re going to be in for a big fight, and the game ensures you’re provided with some necessary materials to help ease your burden.

In addition to the myriad rifles, pistols, shotguns, and grenades are traps, both handheld and found in the levels themselves. For example, Venice has shark corpses rigged up to electrical currents, and when you hit a paddle with a bullet, it thrashes this way and that, tearing apart zombies as it does so. Elsewhere, propellers are turned into dicing death machines, bullhorns are used as lures for explosives, and portable trip mines can explode, incinerate, and electrify the Nazi horde.

Studying the environment and placing traps at key choke points are crucial to keeping the undead at bay long enough to avoid being overwhelmed, and despite the relative slowness of the majority of the undead, they can very, very easily overwhelm you with sheer numbers. Another of the key things that makes Zombie Army 4 tick is how quickly a serene situation can turn nasty, especially as progress is made through the campaign and more and more new zombie types are introduced.

Rebellion has gone all out in producing a wide range of undead. There’s plenty of the rank and file shambling Nazi fodder to obliterate, but other types are introduced at a decent pace. Some are revised versions of enemies from previous entries, while others are new to the series. You have the returning Nazi officers who can summon and resurrect the dead, suicide bombing zombies encased in straight jackets and screaming all the way to their second death, blind, but immensely vicious undead that locate via sound (looking and moving like a hybrid of The Last of Us’ Clickers and A Quiet Place’s foes.), and armor-clad giants that need to be relieved of their metal casing before taking them out more permanently.

There’s many more, and for the most part, they add something positive to the game, and often homage other famous movie monsters. One of these enemy types is an agile, scuttling, feral zombie that attacks in small groups. It first appears during a trip to an underground lab cloaked in darkness. They can run along the ceiling and pounce, which makes the already nervy journey through the murky dark that bit more stressful. These enemies work beautifully in situations like this, but later, when they pop up in more bright and open environments, they’re just an annoyance. It’s the biggest misuse of enemy types in the game, but there are certainly other occasions where it feels like you’re not well-equipped to deal with the myriad threats coming at you. 

Watch Zombie Army 4 in action.

That can be somewhat thrilling, as winging it against the odds makes for an organic experience, but on higher difficulty settings, in more extreme circumstances, it can feel unfair and needlessly frustrating. At least you can improve your character and come back to difficult situations better prepared.

Zombie Army 4 features a larger suite of player upgrades and customisation than before. There’s regular cosmetic changes, including emotes for co-op, but completing certain in-game checklists unlocks mods and upgrades for your characters and weapons that help in the fight against the undead masses.  For weapons, you can better your actions such as reload times, impact damage, and firing rates, while the characters can be made stronger against certain threats such as melee damage, explosives, and the like. The combat, while enjoyable, can get a tad draining with its rinse and repeat feel, but being able to throw in fresh things to the mix helps the replay value no end.

But if anything is going to keep you coming back, and indeed, enjoying Zombie Army 4 to the fullest, then it’ll be co-op play. Four players can join up for the campaign and horde modes to take on the zombie menace, and as you’d expect, it’s a great time. Laughing and joking over each other’s X-Ray kills frequently turns to frantically shouting out warnings and instructions as you attempt to secure your objective against an unearthly mass of inhumanity. As with most co-op experiences, any perceived flaws melt away in moments like these, and a successful co-op game is one that plays to that strength. In solo play, there’s still plenty of tension, anxiety, and giddy glee, but it’s just not as rich as it can be with a friend or three. 

Horde mode boils that down to its base level, giving you the high intensity parts of Zombie Army 4’s campaign consistently, increasing in stress and chaos as each wave ensues. It’s not original, it’s certainly not inventive, but it’s pure co-operative goodness. For many, that will be the reason to come back ahead of replaying the campaign.

One of the most pleasing things about Zombie Army 4 is this simplicity in an age of multiplayer games designed to last for years. Don’t get me wrong, you can get plenty of mileage out of Zombie Army 4’s co-op, and with more secrets, exploration, and progression than ever before, but it’s relatively short-term in a world of ‘Games as a Service’. That can be risky in this day and age, especially when you can’t guarantee a healthy playerbase for months on end (even with DLC layed out for the near future), but if last year’s World War Z taught us anything, you can easily find a willing audience for a simple, yet well-made, co-op horror shooter if you handle it right.

So Zombie Army 4 isn’t ripping up any trees in terms of originality, but it’s the ultimate version of the franchise’s best features. After all, what’s more satisfying than destroying Nazi zombies in stylish, violent fashion?

Zombie Army 4: Dead War review code for Xbox One provided by the publisher.

Zombie Army 4: Dead War is out Feb 4 on PS4, Xbox One, and PC.