Mycelium Benchmark: Gemini 3.5 Flash

Inspired by Simon Willison’s pelican-on-a-bicycle benchmark, I tested Gemini 3.5 Flash with a zero-shot prompt: “Generate an animated SVG of a mycelium network connecting three trees, with nutrients flowing through it.”

With thinking set to medium, the model spent a minute and six seconds and 15,266 tokens on it. It rendered three trees, added cute, glowing mushrooms at their bases, and ran nutrient flows in both directions. The bioluminescent palette is gorgeous. Most nutrients, though, drift in open space. It failed to understand that everything needs to flow through the mycelium network.