They Are Billions stands out as a real-time strategy game that blends base building with intense survival elements in a post-apocalyptic steampunk world overrun by zombies. Developed by Numantian Games and released in 2019, it challenges players to manage dwindling human colonies against massive swarms of infected, emphasizing careful planning and resource management to avoid total collapse.
Gameplay
In They Are Billions, the core loop revolves around establishing and expanding a colony while defending against relentless zombie threats. Players start by constructing dwellings to house colonists, gathering resources like food and materials from the environment, and setting up energy networks with Tesla Towers and power plants to keep everything running. Defensive structures such as walls, gates, and towers are essential to monitor and protect the perimeter, as even a single infected breaching the defenses can trigger a chain reaction of outbreaks.
The game operates in real-time but includes a pause feature, allowing strategic decisions without the pressure of split-second actions. This mechanic supports thoughtful placement of buildings, army commands, and resource allocation. Recruiting mercenaries forms the backbone of your military, each with distinct skills and personalities that add flavor to combat. Upgrading buildings for efficiency and researching over 90 technologies help evolve the colony, while the engine handles up to 20,000 on-screen units, creating chaotic swarm encounters where noise attracts more enemies.
Infection management adds tension; if an infected enters a building, it spreads rapidly, turning workers into threats that can doom the entire settlement. Combat focuses on containing these risks early, using the Imperial Army to clear areas and explore ancient fortresses with a hero unit.
Game Modes
They Are Billions offers two primary ways to engage with its strategy mechanics. The Campaign mode, titled The New Empire, puts players in command under Quintus Crane to reconquer devastated lands through 48 missions spanning more than 60 hours. This narrative-driven experience involves building fortified outposts, destroying infected swarms, evolving colonies with technology, and uncovering the apocalypse's origins via hero-led explorations.
Survival Mode generates a random world complete with unique events, weather patterns, geography, and infected populations. The goal is to sustain a colony for a set duration against escalating threats, including massive roaming swarms. It supports custom games and features leaderboards for comparing scores, with community-created maps extending replayability through the Steam Workshop.
Is It Worth Playing?
With Very Positive reviews on Steam, where 80% of 18,684 English-language user reviews praise it and recent feedback from the last 30 days shows 81% positive out of 163 reviews, They Are Billions holds strong appeal for strategy enthusiasts who enjoy tower defense and base management. The Metacritic score of 77 reflects a solid critical reception, though some players note repetitive elements in longer sessions.
As of 2026, the game remains active with community engagement through custom maps and leaderboards, despite no major updates since its full release. It suits those who prefer single-player challenges with high difficulty and strategic depth, making it a worthwhile pick if you thrive on methodical planning against overwhelming odds in a zombie survival context. If fast-paced action or multiplayer is your preference, it might feel too punishing.
