A busy SOLESIDO town centre with apartments, a clock tower, pedestrians, roads and traffic
WORLD 01 · RAINFOREST BASIN

A rainforest city-builder for PC · hand-built by one person

Build a city. Keep a world alive.

They have given you a valley, five hundred souls and one road into the trees. Every roof you raise comes out of that forest. How much of it will still be standing when your grandchildren inherit the place?

Rainforest Basin · Year 4 · population 1,180 and climbing.

See the valley
51,840hectares of untouched basin
500souls on the first morning
16species that were here first
6generations, cradle to grave
1road in

Your first hundred days

Nobody here has a house yet. They are all watching you.

Five hundred people came upriver on your word. They are sleeping under canvas at the landing while you decide where the town goes — which trees come down, where the first road runs, whether the mill gets built before the rain arrives. Everything that happens in this valley for the next two hundred years starts with what you draw this week.

They will build lives hereWork in the morning, market at noon, the river in the evening.
Something already lives hereJaguar, harpy eagle, howler monkey. They were here first.
And they have to eatClear the fields, or the town starves politely and leaves.

The road to the first roof

Four steps between a standing tree and a family with a front door.

This is the errand the whole valley turns on. Fell the stand. Get the logs out before the track floods. Feed the mill. Carry the timber to the plot where a family has been waiting since spring. Run it well and the town doubles. Run it badly and it stops where it stands.

WOOD CHAIN MONITOR 01 / 04
Harvested timber piles beside a SOLESIDO road FOREST EDGE · THE CUT

THE VALLEY SAYS · TIMBER ON THE GROUND

The saws start at first light.

By evening there is a clearing where the canopy was, and the logs are lying in it. They are yours — but they are also four miles from anyone who needs them, and the forest floor is already going soft underfoot. Cut somewhere your lorries cannot reach and you have simply killed a stand of trees for nothing.

Standing this morning
Gone by dusk
Grows back in
A generation, if you let it
Families and children walking near a SOLESIDO market and apartment buildings THE SECOND GENERATION

Two hundred years, one family at a time

The children you housed will take the jobs you built.

A woman arrives on the first boat, takes work at the mill, marries a man from the farm road and raises two children in a house you approved. Those children grow up, and one of them ends up running the sawmill you founded. Nobody wrote that down in advance. It is simply what a valley does when you keep it worth living in.

Close the mill and watch her walk further every morning. Let the shop shelves empty and watch her family thin out. She will not complain to you about it. She will just quietly make the best of whatever you left her.

A door of their ownOne family, one address, one shared life.
The morning walkOn foot, by car, or on the bus you put there.
Something to eatFull shelves, or a long walk to nothing.

The basin keeps its own accounts

You can have the city. The forest will tell you what it cost.

Every hectare remembers what you did to it — the canopy you took, the soil you compacted, the water you fouled, the air above it. Jaguars need unbroken forest to hunt through. Harpy eagles need the tall trees you were eyeing for the new district. Cut a corridor in half and the animals on the far side simply stop being there, quietly, without a warning message.

Intact rainforest in SOLESIDO
THE BASIN AS YOU FOUND ITClosed canopy, clean water, and something moving in the trees
Large cleared forestry area in SOLESIDO
THE BASIN AFTER YOUYour timber, your bare ground, your decision whether it ever comes back
A SOLESIDO sawmill district with chimneys, timber yards and working vehicles DOWNWIND OF THE MILL

There is weather in this sky

The wind does not care where you put the factory.

Your steelworks throws black smoke. The sawmill adds its own. Out at the edge of town the water plant breathes clean white steam, and it is the only thing here that does. On a still morning it all just hangs over the rooftops. Then the wind gets up, and takes it somewhere.

Build the mill upwind of the houses and you have made a decision about somebody's bedroom window. Move it two streets and you have made a different one. When the wet season breaks, the rain pulls the whole lot out of the air and puts it in your river instead.

Smoke and steamOnly the water plant runs clean.
Wet season, dry seasonThe rain comes and goes all year.
What goes upComes down again, into the water.

Word gets out beyond the basin

Strangers start walking in looking for work.

They do not appear out of thin air. They come up the same roads your own lorries use, in through the handful of entrances at the edge of the map, on foot, carrying what they own. Thirty-odd a day, once your town is worth the walk.

Your own people always get first refusal on every job. Only what nobody local wanted is offered to whoever walked in this morning. They take it, they move into temporary quarters, and for six months they are part of the town without being of it.

Then the contract ends — and about one in five asks to stay. Whether they can depends entirely on whether you ever got round to building somewhere for them to live. If you did, they become citizens: a home, a household, children who will grow up calling this valley theirs. If you did not, they walk back out the way they came in.

32arrive on a good day
6months on contract
1 in 5ask to stay
20youngest who can sign on
Recorded in game · arrivals walking in for contract work
SOLESIDO farms and freight roads
THE FIELDS

Harvest comes once a month.

Then somebody has to load it, drive it in and stack it on a shelf. A full barn out at the farm road feeds nobody in town.

SOLESIDO regional trade warehouse next to rainforest and roads
THE ROAD OUT

You are not the only town in the basin.

Neighbours downriver will buy your surplus and sell you what you lack — if your warehouse is stocked and your road is open.

A large SOLESIDO district with many active construction parcels
THE PLOT

A marked-out plot is not a house.

It needs the timber carried to it, the money paid and a crew that turns up. Until then it is just rope and pegs in the mud.

Working forestry machinery in SOLESIDO
FIELD GUIDE · 108 LESSONSFREE

The part nobody publishes

How I Built SOLESIDO with AI

Not a success story. The whole thing: the childhood drawing in Paint, the rewrite into native C++, the assumptions that turned out to be wrong, the frame rate collapse, the bugs that survived a passing test suite, and the working method that finally stuck. 108 lessons, free, no signup.

“When the AI says fixed, ask: which build, which test, which save, which measured result and which screenshot?”

Run the valley your way

Do not like the odds? Change them.

Wages, yields, how fast a roof rots, how quickly the forest returns — every rule this world runs on is yours to open and rewrite. No install, no account, no modding kit to buy.

SOLESIDO LOGIC CENTEROFFLINE TOOL
SOLESIDO interface controls

Make the mill generous. Make the rain cruel.

Turn one number and see what falls over. Build the valley you actually want to live in, and play it tonight.

See how the rules work
Michal, creator and designer of SOLESIDO CREATOR · DESIGNER · FIRST-TIME GAME MAKER

One person. No studio. No budget.

It started as a green rectangle in Paint.

A canvas flooded green. Blue rivers painted through it. The eraser used as a deforestation tool. That was the whole game, and Michal was a child. Years later he came back to the question underneath it: what if the forest actually mattered?

SOLESIDO is the answer — a city builder about living between the rainforest and everything we want to put on top of it, made alone, in a long and frequently humbling collaboration with AI.

Read the origin story →
SOLESIDO

There is no game over here. Only the valley you leave behind.

The basin is finished. The people are in it. One man is still putting the last roofs on before it goes to Steam — and the day it opens, five hundred souls will be standing at the landing waiting for somebody to tell them where to build.

Windows · coming to Steam · made by one person

Be there for the first boat