How I Instrumented a Bevy Game with Telemetry (Spans, Metrics, Logs)

I wanted to document how to instrument a Bevy game with telemetry, so I ended up writing one. The plan was simple — write a tutorial showing how to integrate Micromegas (a telemetry framework) into a Bevy game. Spans, metrics, logs, the full picture. Problem: I needed a game to instrument. So I built one over the weekend. A Pac-Man clone loosely based on Voltaire's Candide — weapons escalate from brass knuckles to chainsaw, luxury items make you look ridiculous, and the narrator loses his mind as the violence escalates. The final level is a quiet garden with no enemies. But the point is the instrumentation. Why Observability in a Game? Games generate thousands of events every 1/60th of a second. Frame times, physics ticks, AI decisions, input handling — when something goes wrong, println! debugging won't cut it. You need structured telemetry you can query after the fact. Micromegas collects logs, metrics, and traces in a unified format with 20ns overhead per event. It can handle 100k e