For this every player needs to successfully complete every round so obviously having only 2 players and 1 round will make this a lot easier.
From the main menu select 'Start a Party' and press
to continue as the settings are already correct there. Scroll down to where it says 'Random' and change it to
Stunt as for the most part they are easier.
Start the game and providing both players complete the task this will be yours.
You'll also unlock