Hi Stumbler! Dynamitron here to assist you with any gameplay related FAQ ⚡ 
There are 2 main ways you can connect with your friends and / or family in-game.  
A - Normal Game

-You can create a room so that you and your friends can all play together in the same game.
-Party hosts can kick uninvited players if they happen to enter the room.
-Play with in a more competitive environment with other players filling in empty spaces (occasionally bots will also fill in these empty slots)
-Rewards are granted in ''Normal Game'' party mode (Crowns, EXP, Trophies, etc)
B - Custom Game

You can also choose to create a ''Custom Game'' which will present more customizable options but you won't earn any rewards in this game mode. 
Some of the custom game party characteristics are:

-Play in the desired Maps that you want
-Amount of players that will participate
-Choose to fill slots with AI (bots) or not
-In Custom Parties no Crowns or Trophies will be awarded
-Players will also not gain experience points
-If not invited, other players will not fill in the players slots
-If a player wins a custom game party, they will be greeted with a Joker's hat

Note: Currently some Team & Survivor maps are disabled in custom game party if there is only one player in the party (because they can't be played only by one player)

Since the game only has solo mode at this time, do remember that it’s still every man for himself!
Thank you for being awesome!