Mutant Year Zero took me by surprise. When you tap the space bar to switch from the real-time exploration mode to the turn-based tactical mode, it's not considered activating combat. You're not entering into battle. The word “Fight!” doesn't leap out of the centre of the screen. Instead, the space bar is labeled “Ambush” and, while pressing it does indeed initiate a turn-based XCOM-style encounter, the semantics make all the difference.

Road to Eden is all about using stealth to thoroughly scout dangers ahead, then applying that knowledge to maneuver your squad into position for the perfect ambush. Do your research and plan well, and you can take out your target without them (or their cohorts) even realizing what has happened. Proceed without caution and you'll soon be bleeding out, your impatience severely punished. Approached properly, Mutant Year Zero isn't a difficult game; it’s a tight, cohesive tactical masterclass that rewards the diligent player.

Road to Eden depicts a post-apocalyptic Scandinavia where resources are scarce and knowledge of what the world used to be is even harder to come by. Stalkers are sent from the Ark, one of the few remaining hubs of human civilization, into the Zone to scavenge for scrap and fend off the bandits, ghouls, feral dogs and worse that now occupy the ruined towns and suburbs. Everyone, even those safe in the Ark, has been touched by mutation. But Dux and Bormin, the two starting playable stalkers, are different; they're mutated animals, a duck and a boar, respectively.

At first glance, there's a lot you can do to customize each stalker and gear them up to specialize in certain fields, letting you mix and match your active squad based on the task at hand. The limited number of weapons and sheer expense of upgrades means you're forced to make tough choices. Should you spend literally all your weapon parts on the close-quarters effectiveness of Bormin's scattergun, or are you better served improving the ranged potency of Dux's crossbow? You can only afford one right now and, since there's no capacity for grinding, it may be some time before you can afford the other.

Sometimes the decisions are easier. Up against robots? You'll want at least one stalker, probably two, with an effective EMP attack. Up against dogs? You'll want at least one stalker, probably two, with crowd control abilities to prevent their melee rush. If you've done your scouting properly, you'll know what's coming and know which stalkers to swap in and out before you tap that spacebar. But don't tap that spacebar just yet. You're not quite ready.

The Zone is divided into a couple dozen maps networked across southwest Sweden. They're not especially large--bigger than an XCOM map, but hardly sprawling--and typically centered on an identifiable feature: a scrapyard, a school, a subway station, a fast food restaurant, and so on. When you first enter an area you're in exploration mode and free to walk around in real time. When you spot an enemy you can enter stealth mode by switching off your flashlight, thus slightly reducing your visibility but also greatly reducing the distance at which the enemy will spot you. You're still moving around in real time, just slower and more discreetly.

The tension is ratcheted up during this pre-combat exploration phase, as you're tip-toeing into hostile territory, identifying how many enemies await you, what types they are, what levels they are, whether they're patrolling, where those patrol routes take them, where their vision cones intersect, and so on. You've noticed one enemy's patrol route takes him away from the others. You hit F to split up your party and guide them individually into position. Bormin has his back to a tree, Dux is on the roof of a nearby building, and Selma is crouched behind a rock at the end of the unsuspecting enemy's patrol route. He's there now. Time to hit the spacebar.

It's all about the ambush. It's about analyzing each scenario in the exploration phase and identifying which enemies you can eliminate, one by one, without alerting others. But pulling off a series of clean hits isn't always possible. Inevitably something will go wrong--you'll miss that 75% chance shot you were counting on or fail to do quite enough damage before the enemy gets its turn and calls out for reinforcements--and suddenly the whole area is on alert and you're scrambling to improvise a new plan. In these moments of high chaos, when the rug is pulled out from under you, this is where the game really shines.

The tactical combat engine borrows a lot from Firaxis' revival of XCOM and offers as much depth alongside a presentation that ensures all critical information is clearly communicated at all times. And you need to be well-informed, because most of the time--outside of the odd simple skirmish that introduces a new element--there's an awful lot to think about. Enemy variety is key; there are basic brutes who charge you in melee, snipers who hunker down on overwatch, shamen who can call in reinforcements, and medbots who can revive enemies, pyros who flush you out with molotovs, and that's just the early stages. Later, there are high-HP tanks who can ram your cover, priests who can buff fellow enemies or deliver chain lightning attacks, giant dogs who can knock you over and maul you for multiple turns, while others possess mind control powers and more. Tackling groups of enemies drawn from several of these types can be hugely challenging, even when you've culled their numbers with some decisive early stealth takedowns.

The stakes are high, especially on the harder difficulty settings. Your stalkers' health will be measured in single and low-double digits for much of the game, meaning it only takes a couple of direct hits to put them down. Similarly, your weapons can only fire once, twice, or if you're lucky, three times before you need to use up valuable action points to reload. These limited resources echo the post-apocalyptic themes of scarcity and survival while also raising moment-to-moment tactical considerations in combat.

Juggling all the demands of combat, from patiently surveying the field beforehand through to learning how to best counter each enemy type and improvising a new strategy when it all goes horribly wrong, make for an immensely satisfying tactical experience. But as enjoyable as the predefined encounters on offer over the course of Road to Eden's mostly linear story are, it's still a linear story. On a new playthrough, that same map will still feature the same enemies standing in the same spots or running the same patrol routes. Outside of testing yourself against the hardest difficulty and a permadeath mode (assuming you don't opt for these first time through), there's not a lot of replay value to be found.

It's a shame, because the combat engine is so robust I would love to continue pitting myself against some sort of randomly generated map long after completing the main story. Mutant Year Zero's clever focus on stealth and pre-combat preparation reward your diligence, its turn-based combat encounters are complex, and they help bolster its all-encompassing post-apocalyptic atmosphere. It is a superb tactical combat campaign that you shouldn't let sneak past.

[Update, 08/01/2019: Mutant Year Zero: Deluxe Edition is now out on Nintendo Switch, and it includes new expansion, Seeds Of Evil. While this version runs smoothly, it exhibits poor visual fidelity compared to its console and PC counterparts. Whether in handheld or docked mode, a low resolution and blurry overall look reduce the luster of post-apocalyptic Sweden. It also makes scavenging areas for scrap and weapon parts--essential to keeping your Stalkers well-equipped, and already difficult items to spot--a lot harder.

The Seeds Of Evil expansion, also available on other platforms, expands the game's story past the somewhat abrupt ending of Road To Eden. Additional map areas and new enemy archetypes introduce challenging new scenarios; a new character, additional weapons, and upgraded perks give you more options to consider as you plan your ambushes. Seeds of Evil also adds a system that will occasionally repopulate existing map areas with enemies and items, which effectively adds a continual stream of optional encounters and mitigates the base game's issues with replayability. These new additions feel like a natural continuation the game's already robust tactical offering, both in terms of its plot and difficulty scaling, and comes recommended.]