The Binding of Isaac developer recommends backing up your saves, in case any bugs in the beta cause a loss of progress. While a full release for the new features is yet to be announced, the multiplayer functions will be available for two weeks out of each month. For each two-week period, a new opt-in password will be required, and we'll regularly update our guide to let you know what that is.
Posted from: this blog via Microsoft Power Automate.