Zombie strategy where the maths does the scaring, still holding up 7 years on

They Are Billions asks one question and never stops asking it: how long can you hold? Numantian Games built a real-time strategy game around a single pressure — the infected are billions, you are a few thousand — and the tension holds from the first wooden wall to the final horde. It is a survival game in the plainest sense. The colony is the thing you protect, and everything else, every resource, every turret, every expansion, is a way of buying it one more night.

Trailer, via Numantian Games.

A Crater Called Empire City

The setup is steampunk apocalypse. In the late 22nd century, a mutated strain of rabies called Rabies Z turns the world’s megacities into graveyards. Survivors huddle under General-turned-Emperor Quintus Crane, who builds Empire City inside a crater the zombies cannot reach. The campaign, titled “New Empire,” starts 13 years after Crane announces he intends to expand beyond that crater and rebuild a human empire.

You play a colony administrator and military commander under Crane. The campaign runs from the northern Western Seaboard down to the fallen megacity of Mega York, the former New York City. You raise a personal army of mercenaries, renegades and convicted criminals. Two special operatives, Caelus and Calliope, help you recover lost technology and piece together where the infection came from. Crane’s colonies are connected by a railway network.

That origin is worth naming, because They Are Billions does not treat the apocalypse as a mystery to be admired. The virus was a byproduct of an attempt by the world’s leading scientists to use recycled meat from deceased people to stave off a feeding crisis caused by overpopulation. The result also produced mutations — never-ending adrenal surges, overgrowth.

Eight Resources and a Tech Tree

The core loop is base-building under threat. Maps are randomly generated, steampunk in look, packed with zombies. You plan a layout, explore, collect resources and expand while fighting the local infected. There are eight resources to manage: gold, food, workers, wood, stone, iron, oil and energy. Structures and units follow a tech tree and demand different materials.

Infected villages, called Villages of Doom, can be pillaged for resources. The backlash is a swarm. That trade is the whole game in miniature: the thing you want is guarded by the thing that kills you.

Zombies attack at random intervals in small numbers. Larger hordes arrive at set times, and everything builds toward a very large “final horde.” A breach into non-defensive structures is the nightmare, especially in tight or overdeveloped areas where one outbreak cascades.

The enemy roster punishes a single defensive answer. Slow, decrepit zombies are the baseline. Harpies are extremely fast. Chubbies are highly resistant. The Infected Giant has high health, speed and damage and is highlighted on the minimap. Walls, turrets, towers and traps buy time, but tactics have to change with the threat.

The Pause Button Is the Best Weapon

Here is the design decision that makes They Are Billions work. It is a real-time strategy game, but you can pause at any time to plan and issue simultaneous orders. That single allowance turns a genre built on clicking speed into something closer to a planning game. The panic is still there. The pause just lets you be deliberate about it.

Single player only. No competitive scene, no co-op, no second player to blame. Bird’s-eye isometric view, which suits a game about reading a perimeter.

The package spans genres on paper — real-time strategy, role-playing, strategy, indie — and the campaign is where the role-playing shows up, through the army you assemble and the operatives you work with. The survival mode arrived first, in Early Access, and the campaign followed.

Where the Holds Break

They Are Billions is at its best when the map is quiet and you know it will not stay that way. The Villages of Doom are the clearest expression of its idea: greed with a timer on it. The Infected Giant is the clearest expression of its escalation: a problem that demands adapted tactics, not one more wall.

The campaign is the weaker half. The story does the work of explaining Rabies Z and the recycled-meat origin, and that explanation lands as grim satire rather than horror. But the mode that made the game’s name — hold the line, lose slowly, try again — is the one worth returning to.

The score reflects that split. A 7.6 of 10 is a game with a genuinely strong core idea and one mode that outshines the rest.

1. Survival mode — the purest version of the game’s premise.
2. The pause-and-plan system — the mechanic that separates it from the genre’s reflexes.
3. The final horde — the payoff the whole run builds toward.
4. Villages of Doom — risk and reward in one structure.
5. The campaign — the story is worth knowing, the missions are not the reason to stay.

The Numbers Behind the Horde

• Release: Early Access survival mode, December 2017; “New Empire” campaign, June 18, 2019
• PlayStation 4 and Xbox One versions published by BlitWorks, July 1, 2019
• Platforms: PlayStation 4, Xbox One, PC (Microsoft Windows), Nintendo Switch 2
• Developer and publisher: Numantian Games
• Modes: single player
• Resources: gold, food, workers, wood, stone, iron, oil, energy
• Score: 7.6 of 10

The zombie strategy game is a crowded field, and They Are Billions does not win it on spectacle. It wins on a number: billions against a few thousand, and the slow arithmetic of how many walls that buys. The infected are not a puzzle to solve. They are weather. What Numantian built is a game about preparing for weather you know is coming and cannot stop — only survive, or not.

That is why the pause button matters more than any unit in the tech tree. It gives you room to be wrong on purpose. The campaign tries to give the apocalypse a history, and the history is memorable. But the mode that will keep pulling players back is the one with no story at all: a map, eight resources, and a horde with a schedule.

They Are Billions is not the definitive take on the zombie strategy game. It is a sharp, specific one, and the specific part — the crater, the final horde, the numbers — is worth the time.

game review · Numantian Games · RTS · survival mode · They Are Billions · zombie strategy game