I've seen it. M. Night was only a producer. He didn't write or direct it. He came up with the story though. It was a decent thriller that was creepy in parts. And yes, it did have a twist ending I guess. My main complaint about the movie was that the characters were so damn unlikeable! I wanted all of them to die within the first 5 minutes they stepped into the elevator.
I don't know why directors still don't get it. The only way you can effectively scare your audience is if the audience cares about the characters on the screen. It's so simple and they fuck it up almost every time by making the characters obnoxious and mean-spirited.
I do suspect that M. Night stuck his dirty little finger in the script once or twice. There was a scene with one of the employees of the building in which the film takes place. He was the stereo-typical superstitious, crucifix-kissing spanish character. He claimed that when the devil was present, everything went wrong. His demonstration of this was dropping a piece of toast on the floor. When it landed jelly side down, he was like, "See?! It landed jelly side down! I told you!" I thought, what the fuck? That happens to me EVERY time I drop toast with jelly on it. This guy and some of the shit he said had M. Night written all over him.
If Devil had been an M. Night movie, I would have said that he is improving. Well, I take that back. If Devil had been an M. Night movie, I would have never known he had improved, because I would never have seen it. But, it's worth a rent when it comes to video.
*I did get a big laugh, but it didn't come from the movie itself. One of the characters is shown on the floor with their head turned completely around and their neck was twisted in a knot. Right after they showed that, someone in the theater yelled, "What a twist!", complete with accent.
I laughed my ass off.