How it is made

The workshop.

AI disclosure

Designed and directed by a solo developer, built with AI.

Halden: The Cordon is designed and directed by a solo developer and built with AI tools. Every feature was asked for, reviewed, playtested and corrected by hand over months of milestones. It was not generated from one prompt. AI produced the code, the art (drawn by code it wrote), the writing, and the music (made with Suno and owned by the developer). The sound effects are real recordings.

  • The developerDesigned the game, asked for every feature, reviewed it, walked every milestone in play, and corrected or rejected work along the way.
  • The codeWritten with Claude, Anthropic’s AI, working as a team of agents. The game’s own credits say so.
  • The artEvery sprite and animation is drawn pixel by pixel by code that AI wrote.
  • The writingThe in-game text, the notices, the notes and the radio.
  • The musicSongs and hymns made with Suno and owned by the developer.
  • The sound effectsReal recordings: public-domain (CC0) field recordings by people, not AI. Footsteps, doors, weather, animals, voices; credited in the game.

How it is made

UrbanGraph.

A city this size is a lot of code. So we built our own tool for working on it, UrbanGraph: it reads the whole game and shows how every part of it connects. It is made for this one game and is not for download. This is what it looks like.

lines of C#
1,202,859
classes, methods and fields
117,217
links between them
885,728
automated tests
11,487
UrbanGraph, Overview

The whole game at a glance: every project, the pieces the most code leans on, and the biggest ones. It is read again from the code every minute, in about a second.

Made for one game

It reads the game's code with the same compiler that builds it, and keeps up on its own: every minute, whatever changed is read again.

What breaks if…

Every change starts with three questions: what uses this, what does it reach, which tests cover it. Each answer takes a twentieth of a second.

A hub for the team

Who is working on what, where two pieces of work touch the same files, and what has been decided. AI agents write the game's code, many at once; the hub keeps them out of each other's way.

Numbers as UrbanGraph read them on 7 October 2026: 5,423 files, 95 systems, 11 projects.