Private Matches

Private Matches or '''Private Missions" were added in the Augest 7th, 2014 update. They allow private matches so players can play with who they want to as long as they have the password/game ID. The maker of the game chooses the map by clicking the pictures that rephresent each mission. A checkmark bu the bottom-right corner shows you have chosen that map. Once the map is chosen, you can still change. The map starts building when the match-maker clicks the "Start Game" button.

Password
When creating a game, the password is made for you, and is composed of several random numbers such as 56141658. Oddly, if you join a game that does not exist, another player that happens to join with the same non-existant password joins your game. Whoever joins first decides the map. Up to 4 players can join a private match, and otherwise is the same as a normal match.