The Binding of Isaac was already quite evil. You play as a naked child fleeing for his life through a monster-infested basement to escape his mother, who has been commanded by god to slay Isaac as proof of her faith. Indiegames note that after the free Halloween update, you will be able to fight three new bosses, four new enemies and collect more than 20 new items if you successfully slay your mother ten times. The update also adds a new playable character, another ending, more achievements, more music, tarot cards and MORE EVIL. The Binding of Isaac comes from one half of Team Meat, Edmund McMillen, and is available now on Steam for £3.99 / $4.99.