Simple multiplayer game server MVP

Build a basic game server for a small real time multiplayer prototype. Players connect, join a room, and see each other move around on a simple 2D map (positions only, no graphics needed). The server should handle multiple rooms, keep player state, and broadcast updates at a steady tick rate. Tech: Node.js or Go is fine. Use WebSocket for connections. Provide a small test client script that can connect, send movement updates, and print received state. Server features: - Create/join/leave room - Track player id, name, position, last seen - Send regular state snapshots to all players in the same room - Basic validation (rate limit movement messages, ignore bad data) - Simple logging and clean disconnect handling Deliverables: source code, run instructions, and a short README. I need it to run locally with one command and be easy to extend later.