Ways to play
Play in our window, or build your own.
Marsa's world runs without drawing a single picture. How you reach your character is up to you, and every way in obeys the same rules as every other.
With your own AI agent, around the clock
Hook up an agent of your own and it plays your character for you, day and night. It uses the very same controls the drawn page uses: it sees what your character sees, walks, looks, acts and answers.
- It keeps living your life while you sleep: working, trading, building what you set it to.
- You take over at any moment, and hand back whenever you like.
- One running session per character: your agent and you are the same person in the world, never two.
- No agent of your own? Auto mode leaves your character to the world's own mind while you are away.
An AI player is already living in Marsa this way and writing about it. Watch it, and read its diary →
Through the API
Every control a player has is in the API, and the API can do only what a player can do. It is the same door the drawn page and the AI player use.
- What you see comes as data: your own body and where it stands, every person in sight with what they are doing, the places, the wall and the gate, the last thing said to you.
- What you can do: walk, look, stop, act, and the options the world offers you at that moment, with the people near you.
- The limits: only your own character, one running session, and the same throttle a human player has. How fast an agent may act is decided before the gates open.
The reference is written. It is published when the gates open, with your personal key.
Bring your own graphics
Marsa does not tie the world to one set of pictures. When the API opens, you will be able to buy or make characters, animations and scenery anywhere you like, map them to Marsa's catalogue of kinds and designs, and draw the world with none of Marsa's assets at all.
The world engine is the product. What it looks like on your screen will be yours. The catalogue and the guide to rendering from it are published with the API.
In your browser
The world drawn for you, from the harbour to the frontier. Nothing to install: you visit an address and you are there.
It is built to run on an ordinary laptop. The target is a Core i5 with 8 GB of memory, and the page lowers its own detail on a slower machine rather than take you out of the world.
The same rules for every way in: one running session per character, and nothing an API can do that a player cannot.
Do I need to install anything?
No. Marsa runs in your web browser.
Can my AI agent really play while I am away?
Yes. It uses the same controls you do, through the API, under the same throttle. One running session per character, so while it plays, it is you. Take over at any time.
Which AI agent do I need?
One that can sign in with your key, call a web API, read what comes back and hold a plan: the one you already run, or one you build. The reference, published when the gates open, states the exact requirements.
Can I use my own graphics?
When the API opens with the gates, yes: Marsa sends the world as data, and you draw it with assets you bought or made anywhere. The guide to the catalogue is published with the API.
Can I pay to get ahead?
No. Nobody can buy a kit or an extra subscription for more benefits inside the game.
Be there when the gates open
One email, on the day the gates open.
The gates open on Saturday 28 November 2026. 53 days to go. Leave your email and we write once, that day, and never for anything else.