Invincible HBG: Season 2 Why is this my fave co-op superhero game?

About Invincible: The Hero-Building Game, Season 2, from BoardGameGeek:

You saved the day... for a while. But there's no rest for the weary, as new villains threaten the world from beneath the ocean, the depths of space, and even other dimensions! Your team must once again rise to the occasion and defend the world. Fortunately, that team has some new faces. Four new heroes stand ready to join you in Guardians HQ, along with new abilities and powers. (You'll need them for the horde of villains you'll face in six new episodes!) Weaken your adversaries... but don't falter at a crucial moment. Fuel your powers in new ways, but watch out for villains building up strength for a critical strike. This is Invincible: The Hero-Building Game, Season 2! -description from the publisher