Firstly when i went into this film I didn't have a clue what this was about. Not knowing the genre of a film always makes things slightly confusing especially when the film doesn't know what it wants to be. There was a lot of hype around this film due to the Scorsese Dicaprio reunion. I solely went on the fact Caprio was in this to go and watch it and boy was i disappointed.
To put it simply this film was average, one little line at the end of the film made me like it a bit so it got moved up to average as i've seen films do similar things before, but a lot worse. The strange thing is the more inquisitive people will spot the ending almost immediately, ironically almost 10 minutes into the film i started to suspect the ending and this film is looooooooooooong.
Anyway long story short this film appears to be a mystery, was advertised as a slasher and i guess could be classed as a thriller. Fact is it executes all this poorly, the film is not particularly involving, Dicaprio does well and he can't be faulted for his work here. The script was written by the guy who did Mystic River, this guy did a good job in Mystic River and he obviously just has a problem and pads out films, this suffers greatly whereas Mystic River pulled it off in the end.
Basically federal Marshalls are going to an island looking for a missing Psych patient and basically thats about as interesting as it gets, I think if you watched this a second time you'd get way more out of the movie, but lets face it your not supposed to watch a film twice to like it (which i doubt you would). Apparently this film has been delayed by 6 months as it had to be redone or edited or something as it made little sense, consdiering how bad the end result is I'd hate to have seen what they had originally.
Anyway in summary avoid this movie.