Oh man, finally. Multiplayer is up and playable :D! Some compiler issues for the Linux export slowed things down a couple of days. I hope you guys enjoy it with your friends. I will be starting a thread to report multiplayer bugs, should you encounter any.
A couple known multiplayer bugs that we will address before the final game launches:
1. If non-host players quit or disconnect, the host needs to quit as well and resume the game. If not, the pathfinding for enemies gets messed up, which messes up the flow of gameplay. Exiting and resuming keeps everything normal.
2. If resuming a multiplayer game immediately after a play session (without exiting the application), 25% of the time it will fail to let non-host players rejoin the game. This is fixed by restarting the game and resuming.
The Stone Cold update is up next and *should* be out before the end of August. Stay tuned!