First few times I tried to start a game, I entered my name as required. But then it would prompt me for a password while still telling me I could play without an account.

After trying an few times with no luck I tried a more complicated user name, and it let me it. You should give people better feedback when they selected a user name that is already taken. Personally using a user name to create an account is bad, better to use an email address which is unique.

Gave up a couple of turns later when I got into map moving mode and we unable to get out of it to move my units.