

Physical death by defeating blue baby and spiritual death by defeating the lamb. And both of those endings represent a type of death. Both physically and in the spiritual sense. Denying sins in the Bible is also how a lot of people got kicked out of things and otherwise "died". That's just my 2 cents though.ĮDIT: Wanted to add something here really quick, just to clarify. You can not deny death nor one's sinful nature, and doing so only leads to you avoiding the problems rather than dealing with them. In fact, both bosses from those level sections, ? and The Lamb, are things of complete denial. Meanwhile I'm thinking that the running away ending, which comes from killing the Lamb, may be a complete denial of his nature. His demon self suddenly cast off as to be reborn as a better, "clean" being. What if the Eden ending is the one that comes out of the demon ending.

For the Eden ending he's stuck in the box for a bit as it shakes before unlocking. Meaning to defeat the darkness is to accept it. Defeating MEGA SATAN gives you the acceptance ending with Isaac in the box. HOWEVER, something interesting is which ending plays for which boss you beat. In a way, the Rebirth as the title suggests. It's interesting, as usually in Christianity accepting you failings and sins also means you are ready for forgiveness as well. The only thing I'm going to say here though is the Isaac accepting his dark side part. I think this is a great video, and it's got me thinking about a few things as well. It's not literal and in your face, it's very much open to interpretation and you have to think about it, which is something great art often does. Regardless, this sort of thing is why Isaac has one of the best stories in games IMO. I don't remember seeing any reference to Isaac running away anywhere, the only thing that the video uses to support it is Isaac's demon form smiling, which is a bit of a stretch, especially since he's in the process of suffocating to death at the time. The Missing Poster trinket as it appears in the game is all about dying in specific ways, through which you can unlock the Lost, which is another representation of a dead Isaac - you see them every time you die. Most of this seems spot on, but it seems unlikely to me that the missing poster ending refers to Isaac running away, rather than another reference to him dying (most likely suffocating in the chest, after which his mother can't find him, for obvious reasons).
