I Started Building a Roguelike RPG — Powered by On-Device AI #2

Running On-Device LLM in Unity Android - Everything That Broke (and How I Fixed It) In my last post, I mentioned I was building a roguelike RPG powered by an on-device LLM. This time I'll cover exactly how I did it, what broke, and what the numbers look like. The short version: I got Phi-4-mini running in Unity on a real Android device in one day. It generated valid JSON. It took 8 minutes and 43 seconds. 0. Why This Tech Stack Before the details, here's why I made each choice. Why Phi-4-mini (3.8B)? Microsoft officially distributes it in ONNX format - no conversion work needed.