The new expansion for the marvelous The Binding of Isaac is a mixed bag. Stick your hand in and, fittingly, given the grotesque nature of the game, you might find a pleasant treat, a razor blade or a little cluster of dingleberries. Toxic dingleberries. For the first time since its release, Isaac really is creaking under its own weight and Afterbirth feels as overstuffed as a trio of turduckens. It’s not a pretty sight, but there is plenty of meat wrapped around all those little choking bones.