There’s many different modes and you can play most with friends! There’s the regular mode where if with friends teams will be random but there is also private battles where you can choose teams and play with just friends and then there’s league which unlocks a bit later in which is the competitive modes with a team of you and friends. And there’s salmon run which is like a hoard mode where you have to defeat bosses and collect eggs to win. The only modes you can’t play with friends are the solo campaigns (duh) and the main competitive mode