Update
Update 7. November 2018

Allows you to play against your friends in a party

While it doesn't sound like much, this feature involved lots of changes behind the scenes to make it work. Many thanks to the testers!

So what exactly is it? You know can make parties with your friends and choose if you want to play as one team or against each other. Or you leave it to the auto-balance on how your party should be split.

Spectating doesn't work for parties yet, but that will be the next feature we'll be working on after this update.