Hey guys this is my first post! Anyways...

I'm in the middle of designing a side-scrolling video game which is to be collaborative online. I want two people to be able to be on the same level and fight the same bad guys and each person to see what the other person is doing.

The only thing I don't know how to do is structure the game to allow for this networking capability. The connection will be peer to peer, there will be no server in between, unless this is advantageous in some way i dont see. My question is how should I frame this? Should I have one client actually running the game logic and telling the connected client everything that is going on and polling for input from player 2? Should I have both boxes running the game logic and just pass user input accross the wire? I've never quite done something like this before, but I have done all the networking before. If anyone has any recommendations please post! Thanks in advance!