The storyline is a bit disturbing, but it's from the guy that made Super Meat Boy, so that's expected. You're Isaac, a boy whose mom attempted to kill him when approached by the voice of god and commanded to do so by it. He dives into his basement to evade her, and fights what appears to be aborted deformed fetuses, mutilated kids, flies, and blood-laser-shooting walking vaginas, attacking them with his tears. You can also make a deal with the devil (reduction of maximum health) for powerups, or buy items from shops. Powerups are fairly disturbing too, including your mom's underwear, lipstick, and menstrual pad (makes enemies run away from you), as well as a coat hanger through your head, a belt, the heads of your dead pets, pills, and tarot cards.