This might not fit into one issue, but here's roughly what we need to get multiplayer working:
- Handle "other person's gamestate" messages from the server
- Interpolate other person's gamestate with local physics
- Make sure input etc. is only handled for our window
- Display "opponent" somewhere visible on the other screen
- Handle matchmaking on the server
- Play audio when the opponent has a collision
This might not fit into one issue, but here's roughly what we need to get multiplayer working: