Game center real time multiplayer - what to send?

Unity Engine
1

So, I’m planing to develop a real time multiplayer iOS game with Game center prime31 plugin. The game is a space shooter, 2 players max.My question is what data is usually sent to the other devices? I mean there are a lot of possibilites, here are 2:

  • Send the position, state of every object in the scene. I supose this is not the correct/optimal way. Discarted?

  • Send inputs only of the players. Why not? If I choose this way, how would I handle collisions? Make client-server structure so collisions are only calculated on the server device?

2

Game center is not the way to go, use unity build in network functionality instead.

You should send the position to the clients only and the input to the server, the server moves the objects and sends the positions back to the clients.

3

Why isn’t Gamecenter the way to go? What’s the problem?