Multiplayer Simulation Prototype -- 2

I have a game concept that needs to move from idea to a playable simulation. The heart of this project is a solid multiplayer experience—smooth lobby creation, matchmaking, and synchronized gameplay for a small group of players.

Here’s what I need:
• A functional prototype built in a widely-used engine such as Unity or Unreal Engine (I’m open, but stability and future expandability matter).
• Core networking layer—authoritative server logic or peer-to-peer, whichever you recommend to minimize lag and cheating.
• Basic menu flow: host game, join game, in-session chat, and graceful disconnect handling.
• Clean, well-commented source code plus a short setup guide so I can compile and test locally.

Nice-to-have (not mandatory): a lightweight physics interaction or placeholder AI bots for empty slots—let me know if that fits naturally into your approach.

I’ll supply any art or audio placeholders you need; your focus is the simulation logic and multiplayer architecture. If you’ve shipped or prototyped networked games before and can demonstrate that experience, I’d love to see it.