Trout pay by the kilo. Koi pay by the eye. A young koi only half-shows what it will become — seeing it early, and culling the rest, is the job.

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Coming Soon To Early Access

The developers of this game intend to release as a work in progress, developing with the feedback of players.

Note: Games in Early Access are not complete and may or may not change further. If you are not excited to play this game in its current state, then you should wait to see if the game progresses further in development. Learn more

What the developers have to say:

Why Early Access?

“This game lives or dies on its numbers. How fast a trout gains weight, how hard oxygen and ammonia push back, how often a young koi turns out to be worth keeping — none of that can be tuned in isolation. I need people playing it, failing at it, and telling me where it feels wrong. That is not something one person can simulate alone.”

Approximately how long will this game be in Early Access?

“6 Months approx”

How is the full version planned to differ from the Early Access version?

“The core loop will stay the same. What I plan to grow during Early Access is the depth around it.

I would like to add more koi varieties beyond the Gosanke, with their own judging criteria, along with more equipment and filtration options and more freedom in how the hall is laid out. I am also looking at more customer types and contract structures, so the market pushes back harder as the business grows.

The part I care about most is the economy. Right now the numbers are mine alone. The goal for 1.0 is a balance that has survived contact with players who break things I never thought to try.

Plans may change as I learn what actually works in play. I would rather adjust the direction than ship a longer list that does not hold together.”

What is the current state of the Early Access version?

“Playable and complete as a loop, not as a package. You can raise trout, grade and cull koi, breed koi, manage water chemistry, take customer orders by email, and deliver on schedule. The systems work. The content is thin and the balance is unproven, and that is exactly what Early Access is for.”

Will the game be priced differently during and after Early Access?

“Yes. The price will rise when the game leaves Early Access. Buying now costs less and helps decide what the finished game looks like.”

How are you planning on involving the Community in your development process?

“Through the Steam forums, a Discord, and public patch notes. I am one person with a full-time job elsewhere, so I will not promise instant replies — but I read everything, and the balancing decisions will be made in the open.”
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This game is not yet available on Steam

Planned Release Date: 2026

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About This Game

Two economies share one facility. They do not share a strategy.

Trout are volume

You raise rainbow trout to weight and sell them by the kilo. The margin is thin
but predictable — as long as the water holds. Trout demand cold, heavily
oxygenated water, and they do not forgive mistakes.

Koi are judgement

A koi's value is not in its weight. It is in grade — pattern, colour, body
conformation — scored from pond quality to show quality. A single fish can be
worth a hundred trout, or almost nothing.

Reading a young koi

A young koi does not show you what it will become. It shows you a range:
pond quality at the bottom, show quality at the top, and a price estimate
stretched across everything in between. The younger the fish, the wider the
guess.

You have to commit anyway. Keep it, and it eats — every day, for up to two years,
at your cost. Cull it, and you may have thrown away the best fish in the building.
The estimate only sharpens as the fish matures, and by then you have already paid
to find out.

That is the game: not raising koi, but deciding which ones are worth raising.

Water is the constraint

Every tank runs on the same three pressures:
  • Oxygen has a corridor. Too little suffocates. Too much causes gas
    bubble disease. You pay for aeration by the kilowatt-hour.
  • Ammonia climbs when you overfeed. Every handful of food is a bet
    against the water.
  • Temperature is a single master control — and it is what separates your
    two species. Warm for koi, cold for trout.
Safe. Stressed. Critical. Watch the zones, or watch the growth stop.

Customers write to you

Orders arrive as email on the facility PC — a small in-game operating system with
mail, a calendar, and banking. A buyer names a price and a pickup date. Accept or
decline.

Accepted jobs land in the calendar. No Sunday pickups. When the day comes, net
the fish, move them into transport tubs, and get them to the loading bay — but not
too early. Tub water is bad water, and the fish know it. Miss a date and you pay
twice: in money, and in reputation.

The pressure is the point

Electricity for aeration. Feed. Water changes. Fixed costs that arrive whether
your fish sell or not. Every mediocre koi you keep out of hope is a mouth you feed
for nothing. The economy does not force you to cull — it simply makes sentiment
expensive.

Made by one person

Aquaculture Simulator is built by a single developer in Germany, in Godot 4.
There is no publisher and no team. It launches in Early Access because the
systems are done but the balance is not — and balance is the one thing a solo
developer cannot test alone. What you see is what there is, and it will grow with
the people who play it.

AI Generated Content Disclosure

The developers describe how their game uses AI Generated Content like this:

Some of this game's assets were created with generative AI tools and then integrated by hand: the fish models, the facility hall, and the tanks. Some in-game text, the tutorial and the customer emails, was written with the help of an AI language model. All other assets (music, sound, icons, textures, remaining UI) are hand-made or CC0. Every game system, the water simulation, koi grading, economy, customer and calendar logic, is hand-written code. No generative AI runs at runtime; nothing is generated live while you play.

System Requirements

    Minimum:
    • OS: Windows 10 (64-bit)
    • Processor: Intel Core i5 (4 Kerne, ab ~2017) oder AMD Ryzen 5 gleichwertig
    • Graphics:
    • Storage: 2 GB available space
    Recommended:
    • OS: Windows 11 (64-bit)
    • Processor:
    • Graphics:
    • Storage: 2 GB available space
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