Is Mom nice? (Spolier Alert)

[Raf]

I get that Mom beleives God (Satan) wants her to kill Isaac and in ending 15, she makes a missing poster of isaac and can be seen in the hills looking for him. What happened that made Mom turn back to normal

[ijones72(ninja08)]

everything that happens in the game happens in issac's imagination.issac's mom was never evil.

[Soverine]

Alternatively, she put the poster up to appear to me a panicked mother, and she was in the fields to bury her son. You see her looking around to make sure nobody sees her act.

They don't always throw everything straight-forward at you. A lot of it is intentionally left open to interpretation. Don't take any "Isaac lore" too seriously. Ever.

[Binkie McFartnuggets]

The truth for me is somewhere between your guys´ interpretation. The mother was abusive and all that, however she has that syndrome type of thing that when the kid leaves, she has noone to ♥♥♥♥ up his life anymore and switches to the role of caring and abandoned person

[Cymorg]

She wants Isaac back so she can be sure he's dead. God told her to kill him, not to let him get away from her.

[Slindish]

God told Mom "Bring me your Son"
Mom said "God you must be putting me on"
God said "No"
Mum said "Fine"
God said "You can do anything you want Mom but,
"Next time you see Isaac you better stomp."
Mom said "Where do you want this killing done?"
God said "Down in Necropolis Mom."

[wckowalski]

I think he was missing because he was in the chest, and she didn't think to look for him in there.

[Bite]

She put up the poster so people wouldn't go looking for Isaac, after all, we know he becomes the weird little devil in ending 16, all the serious endings seem to point towards that, so basically:

1: Satan commands Mom to kill Isaac.
2: Isaac goes into the basement in order to escape.
3: Isaac doesn't manage to defeat Mom, God knocks her out with a Bible.
4: Isaac goes within Mom to finish her off, which he does.
5 A: Isaac is taken by Satan and struggles to fight The Lamb, which is Isaac's darkness as result of Satan's influence.
5 B: Isaac rejects Satan and tries to hide within his chest and eventually sofocates, but does become the little imp from ending 16.

So regardless, it seems that Satan wins, and it also seems that Isaac doesn't manage to kill Mom in any scenario, it would be reasonable to think that in order to cover up the little devil living in her basement, Mom, still under the influence of Satan, put up Missing posters around town so people would think that he simply went missing, instead of being part of a satanic ritual.

All in all, when people say this all happens in Isaac's head, I have a lot of trouble thinking Isaac would have any knowledge about the seven deadly sins, the horsemen of the apocalypse, medical conditions such as teratoma, proptosis, etc, I believe the game is very bizarre, but honestly, I don't believe it's all in his mind, nor that Mom becomes good at all.