Basically it looks like a normal fantasy animation movie, but it actually has a deeper meaning. It interprets the procedure of mind control for leaving pain. An alternate reality that provides so much comfortableness that one simply just ignores reality and wants to live in that world.
But the 'other mother' from Coraline's alternate reality is a witch who wants to trap her forever.
Each time Coraline went to that alternate world she remembers everything. How she went, what she has done, the beauty, the horror. At a point, "other mother" trapped Coraline's parent using the same way she provoked Coraline to enter in her world (using dolls). Then Coraline rescued her parents through some events, but her parents can't remember what happened? Question is why not?
If Coraline can remember everything why can't they? What's the hidden meaning of it from the viewpoint of mind control? Coraline even saw snow in their hair and jacket, so it wasn't a dream. They were actually trapped in the alternate reality. They wrote "HELP US" inside the mirror. Still they can't remember anything. What am I missing here?