Details: Originally released in 2010. Spent about eight hours playing through it. Official site is http://www.rockstargames.com/reddeadredemption/dlc/undead
Red Dead Redemption: Undead Nightmare is a stand alone expansion to Red Dead Redemption. That means you don’t need to buy the base game in order to play this. If you loved the base game, then you should play this. Otherwise, you won’t miss anything by skipping this expansion.