Co-op multiplayer won't work

[Cree]

Neither my friend nor I can get this to work.

Are there some specific ports which we are meant to open? It's just stuck on 'awaiting connection' for both of us.

We've both tried enabling the DMZ mode on our routers to circumvent the need for port forwarding, but that won't work either. We're both running it as administrator and we've both set it to run in XP SP3 compatibility mode. We've also tried using Hamachi, but to no avail.

When we check the 'game info' on Steam, it tells us that we're on the 'home' IP (127.0.0.1).

There is absolutely no documentation for this game. I remember it working at some point in the past, but it doesn't anymore.

Any thoughts?

[blahling]

I would love to find out how Co-op plays on this game.