After the game launched and experienced very high traffic, players realized that it was impossible to join their friends due to a very large number of lobbies to process. We are currently adding an invitation feature through the Steam overlay to bypass the problem. If you cannot find your friend's session, please update the game to the latest version (1.7.2), ask them to send you an invitation through the Steam overlay and accept it. We apologize again for the inconvenience.
Source: Steam Community (opens in a new tab)
Build and release context
Recorded Steam release date:
Within one calendar day of this post (UTC). The listed date does not establish an exact launch time.