They Are Billions

They Are Billions

Numantian Games · 2019 · Base Building, Colony Sim, Strategy, Zombies, Survival

PC
Very Positive85% · 45,94777Metacritic1,916playing now
Best price 81 Great time to buy
$5.52-84%
$33.94lowest tracked $5.22
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Trailers & screenshots

About They Are Billions

✦ AI summary

Build and defend human colonies against billions of infected in this real-time strategy game set in a post-apocalyptic future. Manage resources, construct fortifications, command mercenary armies, and survive massive zombie swarms across a 48-mission campaign or endless procedurally-generated maps, all with the ability to pause and plan your every move.

They Are Billions is a strategy game in a distant future about building and managing human colonies after a zombie apocalypse destroyed almost all of human kind. Now there are only a few thousand humans left alive that must struggle to survive under the threat of the infection. Billions of infected roam around the world in massive swarms seeking the last living human colonies.

Campaign: The New Empire - Available now!

Lead the campaign under the orders of Quintus Crane, ruler of the New Empire, and reconquer the lands devastated by the infected.
  • 48 missions with more than 60 hours of gameplay.
  • Build fortified colonies to survive in infected territories
  • Destroy the swarms of infected with the Imperial Army.
  • Make your colonies evolve with more than 90 available technologies.
  • Explore the ancient human fortresses with your Hero.
  • Discover the story behind the apocalypse... how did the pandemic start?

Survival Mode

In this mode, a random world is generated with its own events, weather, geography, and infected population. You must build a successful colony that must survive for a specific period of time against the swarms of infected. It is a fast and ultra addictive game mode. We plan to release a challenge of the week where all players must play the same random map. The best scores will be published in a leaderboard.

Real Time with Pause

This is a real-time strategy game, but don’t get too nervous. You can pause the action to take the best strategic and tactical decisions.
In Pause Mode, you can place structures to build, give orders to your army, or consult all of the game’s information.
This game is all about strategy, not player performance or the player’s skill to memorize and quickly execute dozens of key commands. Pause the game and take all the time you need!

Build your Colony

Build dwellings and acquire food for the colonists. They will come to live and work for the colony.
Collect resources from the environment using various building structures. Upgrade buildings to make them more efficient.
Expand the energy distribution of the colony by placing Tesla Towers and build mills and power plants to feed the energy to your buildings.
Build walls, gates, towers, and structures to watch the surroundings. Don’t let the infected take over the colony!

Build an Army

What kind of people would want to combat the infected?
Only the maddest ones. Train and contract mercenaries to protect the colony. They demand their money and food, and you will have to listen to their awful comments, but these tormented heroes will be your best weapon to destroy the infected.
Every unit is unique and has their own skills and personality – discover them!

Thousands of Units on Screen

Yes! They are billions! The world is full of infected creatures… they roam, smell, and listen. Every one of them has their own AI. Make noise and they will come – kill some of them to access an oil deposit and hundred of them will come to investigate.
We have created our custom engine to handle hordes of thousands of the infected, up to 20,000 units in real time.
Do you think your colony is safe? Wait for the swarms of thousands of infected that are roaming the world. Sometimes your colony is in their path!

Prevent the Infection

If just one of the infected breaks into a building, all the colonies and workers inside will become infected. The infected workers will then run rabid to infect more buildings. Infections must be eradicated from the beginning, otherwise, it will grow exponentially becoming impossible to contain.

Beautiful 4K Graphics!

Prepare to enjoy these ultra high definition graphics. Our artists have created tons of art pieces: Beautiful buildings with their own animations, thousands of frames of animation to get the smoothest movements and everything with a crazy Steampunk and Victorian style!

DLC & expansions

🎁 Complete the collection

Base game + 1 of 1 DLC at today's best prices.

$12.51
to own everything

What Steam players say

Recent verbatim reviews from Steam — separate from playze.io community reviews below.

Not recommended Jul 10, 2026
Game is "deliberately HARD CORE IRON MAN ♥♥♥♥ YEH SO COOL". In other words, you have to waste hours and hours repeating tedious builds under tight constraints, with no progression in the interim. No saves, no checkpoints, nothing else to do but retry the next mission in its entirety. The flow is basically, spend 20-30 mins in relative safety, furiously racing to expand while microing patrol paths on your few starting units to cover the perimeter. You start making military, start to move out, add more patrols, build walls. In the next 30-90 minutes you either lose your entire base because one zombie touched a hut for 3 seconds (no you can't stop it, just restart the mission if you see one of your buildings turn green), or you lose because the jank terrain and building clutter made it difficult to effectively wall the direction the scheduled horde came from. Rinse and repeat until you know where the resources are and where the best points to wall are. Its kinda like Dark Souls. It's not actually hard. It just feels that way because in order to learn the game you have to make mistakes, and any mistake costs you hours of time. You don't feel good when you beat it, because you ba…
3 found this helpful
Not recommended Jul 11, 2026
fun, but there is 0 room for error, no way to load a save from 5 minutes ago to fix said error, and every time you fail your score gets a negative multiplier.
1 found this helpful
Recommended Jul 12, 2026
I don't recall even playing the game, and I don't even own it. But this is a certified banger.
Not recommended Jul 11, 2026
Tried to pick up this game multiple times. Its such a slog. The forced Iron man mode should be a choice not forced. The top negative review is very accurate. Losing a 3 hour session because one zombie in the fog of war destoyed your hunters hut or your tent (which you have to build a million of them) is....not fun. WHY are the track running thru the middle of your camp preventing you from building good defences? WHY does it start you in the middle of the map which is always the worst spot? Like I really want to like this game but it could have just been made... better. Dont get me started on the skill tree. Just skip this one. much more fun rewarding less wanting to pull your hair out RTS titles
Recommended Jul 11, 2026
they... keep... comeing o.o 10/10 rts
Recommended Jul 10, 2026
Just brilliant.

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