The start screen rendered perfectly — five biome cards, a Ghillie Pass toggle, scanline overlay — and then you click a biome and nothing happens. The API key was a placeholder. Dropped in a real Gemini key and the two-stage pipeline lit up: image generation, then structured JSON analysis for bounding box, hints, and nature facts. But the game loop was broken in three places. Timer was static — never ticked. State never reset between rounds. And the bounding box coordinates came back in two different scales (0–1 vs 0–100) depending on which way Gemini felt like answering. Fixed the timer with a setInterval effect, wrote a proper reset callback, and added normalization that detects which scale Gemini returned and converts to percentages. Three biomes tested, three clean rounds. The difference between "this might work" and "this actually plays" was about 30 minutes of debugging state management nobody thinks about.