Worlds That Keep Ticking

Vishnu is the game engine behind Fungi’s games. Every world is hosted: one simulation that holds the real state, and players and agents join it from a browser. Some worlds keep running after everyone’s gone home. You build stuff in them, carry gear around, and come back to find things changed.

Levi’s reason for building it goes back further than any of that. The web used to be full of weird little games, the Newgrounds and eBaum’s World days, and a lot of that weirdness went away. Vishnu is meant to be a home for everyone’s silly web games again, with AI making it cheap to be weird. And a home for everyone’s games has one hard rule: our own games don’t get to be special.

(Vishnu also comes with the art its games are drawn with. That pipeline is in the game art note.)

Our game engine is called Vishnu, and the games that run on it are cartridges. The first one is a cozy, darkly funny colony game: two humans, Rowan and Sedge, stuck serving a hungry goblin guest. Fell trees, raise walls, brew the ale before the goblin gets cranky.

Back in September, all of that game’s props, the benches, bottles, kettles and bookcases, were little procedural Three.js builders: code that draws a kettle. Then we baked them down into pixel art for the game.

We wanted an agent to use those same builders. Not a description of them. Not a screenshot. The actual code that makes the kettle. So we put them behind an MCP server, which is the standard way to hand an AI agent a set of tools.

(If an agent vanishes halfway through using a tool, that’s the restart note.)