Previously you could only invite a friend on steam by opening the game through steams "Add non steam game"
Now you can play with just steam installed and the game will work fine

Some other patch notes:

Patchnotes:

Fixes:

Exiting menus back and forth should be seamless

(Leaving a match as a host) (Alt f4 or quitting normally wont break/crash the game)

(Leaving a match as a player) (Alt f4 or quitting normally wont break/crash the game)

(Creating new lobbies and or joining other lobbies) (Alt f4 or quitting normally, Joining through steam in the lobby screen)

- Weapons now don't have a loading time when you equip them, they equip immediately

- Performance have been improved by drastically reducing method calls and increasing data caching

- Correct color representation with color picking sliders

Known issues:

- Joining a match in progress will break the game