A camera controller used to take Jóhann five to eight hours to build. Now it takes ninety minutes. Next time, it'll take seconds.
That's the thread running through his Usable Fragments talk on using Usable for game development — and the honest part is where he starts: handing the keyboard to an AI agent, after years of hand-coding games, was mentally hard. But once you push past it, you realise how much faster you're actually moving.
It started at a GameJam
The first experiment was building a real game. At the Global Game Jam, Jóhann and Hanna set out to make something with Claude Code and Usable, and ended up with Infinite Memory — a live, multiplayer .io memory game where hundreds of people play at once. It's been running since January.
The workflow that made it work wasn't a single magic prompt. While Claude Code implemented a task — pulling the team's standards and structure from Usable as it went — Jóhann worked a problem in parallel in Usable Chat: how do we do infinite scrolling, how do we flip these cards. Not a one-shot prompt, but a dialogue. Push back, get a better idea, go back and forth until it's right — and then: "document it." The solution lands in Usable, and the next task picks up with all of it already in context.
A workspace that compounds
Then he went further and built a dedicated Game Dev workspace. A throwaway "napkin idea" becomes a Game Concept. A skill turns that concept into a full Game Design Document — by relentlessly asking a hundred questions until the game is actually specified. The GDD fans out into features and tasks.
Underneath sits the part that makes AI-written code last: coding standards, plus a growing library of recipes ("how do I build a camera controller") and solutions ("we hit this bug, here's the fix — remember it"). Every loop writes back, so the system gets better at making games the more you use it. That's why the camera controller went from a day's work to ninety minutes to, eventually, seconds.
In the new flow, Jóhann develops through Claude, which drives the Unity editor over MCP, while he stays in Unity making the creative calls — play-testing, tuning the feel, deciding the character moves a touch too fast. The agent carries the programming load; the human keeps the taste.
One more thing: Usable inside the game
Because it was suddenly so easy to build, Jóhann tried something the tools aren't built for: putting Usable inside Unity. During the Tonik GameJam, that became The Undelivered — an interrogation game where you try to break a suspect into confessing. There's no Usable Chat window bolted on the side; the chat is rendered right into the game's look and feel. And thanks to embeddable Usable Chat, the AI doesn't just answer — it reaches back into Unity and sets the character's mood, choosing from sixteen of them as the conversation turns. The AI lives inside the game.
Watch the full talk
Jóhann demos all of it, and digs into when to define skills, how testing actually works, and why everything staying as portable markdown matters. It's the fourth and final talk from Usable Fragments 2026.
You can viably build games with Usable — and drop your own reactive AI agent right into them → usable.dev
Watch the full series → Usable Fragments 2026 on YouTube