Cactus Sentinel

Sentinel is a stealth game you play with your voice — and can play with your eyes closed. Say "run to the chest", the hero moves, a giant eye watches. Blind and low-vision players get a version with spoken guidance and audio cues instead of a screen. Everything runs on the player's own machine: no cloud, no GPU, no per-request cost, and no audio ever leaves the device. Meta's models are the teacher in the teacher–student recipe behind the two models that run the game — Needle 3 for turning speech into typed tool calls, Whistle for speech-to-text. We wrote the missing piece: a zero-allocation C# inference engine that runs them inside a 60 Hz Unity game loop (faster than the vendor's native C++ engine, 660 parity tests), plus the game, the voice-first menu and the Unity package. Meta's coding agent built it with us.