Physarum is an agent-based simulation inspired by the remarkable behavior of Physarum polycephalum, a unicellular organism capable of solving complex problems without any centralized control. Thousands of simple agents interact within a continuous, borderless field — sensing, turning, and leaving trails behind. From this minimal rule set, mesmerizing, organic structures emerge: branching networks, pulses, voids, waves. What looks like life is built from logic. This simulation is not programmed to draw — it grows.