Idle · strategy · beta
Every living thing is just a host that does not know it yet.
You are a fungal spore from space: spread your network over the planet, region by region, while humans research, burn and strike back.
For millions of years you have drifted through the dark, asleep in the cracks of a rock, until the gravity of an alien planet catches you. You choose where the rock lands, and the network starts from there: threads grow through the ground while you draw MynEnergy from plants, animals, water and people, and evolve with it. The landscape changes before your eyes: wherever you go, a purple web and fruiting bodies grow, and the soil slowly wears out.
Clicking and upgrading is not enough. Worn-out soil gives little, winter and floods arrive, and people notice you, start researching and deploy what they develop, one thing after another: flamethrower squads, fungicide, firebreaks, quarantine, drones, bombers, missiles and finally the vaccine. Strikes are announced in advance, so you have to decide fast: where to pull back, what to sacrifice and what to attack first.
Eight increasingly hard regions lead to the final battle, each with a new opponent and a different goal: infecting cities, growing across islands, a vaccine race against the labs, a fight with another spore, and at last taking the command centre. Conquered regions keep working for you while you are away, and in them automations can take over the decisions too.
In every region you choose where the rock lands. Each of the seven landing sites gives something and takes something: the Ancient Forest pays well from plants, the Deep Mountain Cave halves the alarm but you grow more slowly, and at the edge of a town you can infect people right away, with triple the alarm.
Plants are a steady income, water carries cheaply, an infected animal goes where you steer it, and birds and airline passengers carry spores far away. People are the most valuable hosts, but harvesting them causes great alarm.
Alarm, order, research and 16 technologies. A countdown warns you of each strike, and one button pulls you underground out of the way if you have the spores for it. Research can be sabotaged, and labs can be destroyed.
You give orders to infected settlements: carriers take spores to other cities, harvesting gives triple energy, sleeper agents sabotage in secret, and the symbiont strain can also choose coexistence. Riots break through a quarantine.
Spring, summer, autumn and winter follow each other, rain, wind, fog and floods arrive, the soil wears out and fire spreads. In the harder regions you also have to overcome the sea and the mountains.
A quiet valley, farming plains, river cities, an archipelago, a mountain republic, a metropolis, the other spore and the military continent. Each teaches a new rule and has its own victory condition.
You choose one strain per run: Stealth, Aggressor, Symbiont or Mind-infector. Stars earn genome points, which unlock 16 lasting traits.
Eight automations can take over the work, but the decision-making ones only work in regions you have already conquered. While you are away the network dreams, and conquered regions produce primal sap, which buys upgrades for the whole planet.
Six hard challenges, a daily planet that is the same for everyone, 18 achievements and two endings: Extermination or Symbiosis. What decides it is whether anyone is left to live with.
Beta. The game can be played to the end, but so far the numbers have mostly been measured with bots: the bot that buys the cheapest upgrade never won in regions 2–8 (0 out of 42), and the planning bot always did (42 out of 42). Very few people have tried it, so the numbers may change. Bugs and ideas are welcome on Discord.
Your save is stored in your browser, on this site. Clearing your browser data also clears the save, and the game has no save export.
Made for desktop, with mouse and keyboard. It also starts on a phone: in portrait it is cramped but usable, in landscape the interface covers the playfield.
The game needs a browser with WebGL2 (a recent Chrome, Edge or Firefox). You can turn the sound off with the button in the bottom left corner.
Mycelium Idle runs in your browser, with no install and no sign-up.
