"The Shutter Island" the movie

First of ALL, Happy 4th of July Everyone!!!! After watching "Avatar" on DVD, I felt like I needed to watch another film. SO i went to look for something that's horror, suspense, or maybe some thriller. I came across "Shutter Island". I heard some reviews from the radio station last year, and there was postive and negative feedbacks from the hosts. So I guess, let's try watching this one.
I would have to say this movie is more of a drama to me than more of a thriller after the whole ending and learning the story behind it. Maybe a little suspense here and there, or maybe it just didn't work for me...whatever.
I would give a lot of Kudos to the Plot twist, since it has excellent creativeness to an extent. you would have to pick a side, wait for the movie to finish and be proven right or wrong. ALso the dreamlike illusion effect, to describe a certain past was cool too.
Anyway the story is about two federal marshall called up to the island that provides housing for the criminally insane as a psychiatric institute. They were called to Island due to a recent dissapearance of one of the prisoner that vanished out of her like a bubble. As they asked questions around, things becomes suspicious of the people that work there. They start to wonder if they are the one investigating the actual crime or they are ones being investigated.