What it is
Everything is terrible is unlocked once you beat moms heart for the 5th time. It's supposed to make the game harder
for the player you should notice a difficulty spike once you beat moms heart for the 5th time.
What it does
Everything is terrible makes champions more common, alternate bosses more common, curses happen more often, makes new foes appear in the game, and makes bosses only drop 1 heart after the fight instead of 2