I have two STEAM accounts, each with Guns of Icarus purchased with the intention of playing together in the same room. Every time I hit the multiplayer button on one computer, it seems to kick me out on the other. I usually get "There was a problem connecting to the multiplayer server;Too many login attempts; Wait a minute, then try again"

Is there some IP address checking silliness?

No, there's no IP address check. Do you somehow have the same username on both accounts?

Ah hah nice call! Thanks that worked. The game uses Steam's "Profile Name" as the username, and expects it to be unique eh? It defaulted to the same thing - the first part of my email address on both Steam accounts. I changed both profile names in my Steam->Settings->Friends and then started the game and no longer got booted instantly. Hope this helps someone else.

Does the username == Steam profile name have to be unique globally, or just behind the same router? That could easily cause conflict since it's user entered and Steam doesn't enforce uniqueness.

At the moment the servers will only allow one user to use a given username at a time, so it's possible but somewhat unlikely (two users with the same name would have to be playing at the exact same moment). I'll see what we can do to fix this in a future release.

It would probably suffice to add a more informative message or at least add it to known issues. Hopefully this thread helps anyone in my same unlikely scenario since I got no results when googling the error message.