Ending is not well-explained

Rating: 9/10 (15 April 2016)

spoiler alert!
This is NOT a demon obsessed movie, but it made itself look like one. The idea is not new. Many good horror/thriller movies have similar story, for example, hide-and-seek. Nonetheless this movie has a pretty good style of story telling.
Many audiences don't like a confusing ending that's not well-explained. Unfortunately this movie falls into this category, which I actually like a lot. Hints for the true story are between casual lines and are sufficient for a viewer to get a rough idea what's going on.
If you don't like to solve the puzzle of the hidden meanings in the graphics and in conversation, then don't watch this movie.