I'm sorry to say that it appears as though many of the reviewers didn't grasp Messrs. Charbonier and Powell's intent and that's a shame because this movie is better than it wants to be. It is ambitious and layered.
The actors did a fine job, especially Ezra Dewey. The kid has quality. Rob Brownstein was very convincing as a concerned and loving father.
The 'trauma responses' aspect of the movie is what motivates Ezra's character and that storyline is very nicely tied up at the end.
The ambition is crossing the genres of Horror and Psychological Drama with a bit of Mystery. It's not so much Thriller nor slasher Horror (though there are a couple slashes).
The lore of the Djinn is almost always underscored by the 'be careful what you wish for' maxim, which is hinted at very subtly and uniquely in a delicate philosophical exchange between father and son fairly early on.
Personally, I loved the very contained element of the small apartment for the setting of the majority of the film. You can almost imagine this being done as a stage play.
I'm sorry that there are so many negative reviews for what is clearly something slightly askew from the common fare thrown about as modern Pop Horror; this is a solid 7...
...it's just not for everyone.