Resident Evil Zero takes place prior to the events of the first Resident Evil. The game features police officer Rebecca Chambers and Billy Coen, a prisoner on death row. The duo must work together to survive a virus that has resulted in a zombie outbreak. The player can switch between the two characters at any time for the duration of the game, a feature called "partner zapping." Each character possesses unique abilities. The player is also able to control both characters simultaneously, or have them separate to cover more area when exploring.
Earlier this year Capcom released Resident Evil HD, a high-definition remake of 2002's Resident Evil, which was a GameCube version remake of 1996's Resident Evil for the PlayStation. Resident Evil HD has sold more than one million units worldwide, setting a new record as the "biggest-selling day one digital title" on the PlayStation Network, according to Capcom. The game is also Capcom's fastest selling digital title in the company's history.