The second twist ruined it for me
*Obvious spoiler alert*
Ok, so we find out that all of it is just a clash of different personalities inside Malcom's head, right? So he destroys the killer personality, Paris gets to live, and this is where it should have ended. It made sense for Rhodes to be the killer. And i'm not a sucker for happy endings, but this would just be a sensible way to end the story and in itself would make a brilliant (8/10) movie in my book.
But no, they just had to insert that ridiculous scene where they show how it was really the boy who killed everybody in a half-assed manner that looked like it came from a parody of the actual movie. Honestly, my friend and I burst out laughing at it, even though we were completely invested through the rest of the movie.
Still a good movie, but could have been better without the unnecessarily convulted twist just for the sake of it.