So Much More Than The "Surprise Ending" Movie Advertised

Rating: 9/10 (12 March 2017)

By and large, I am a huge fan of films in the same genre of Shutter Island (thriller; big surprise at the end). A few of my favorites that come to mind are The Sixth Sense, The Others, and Identity. Shutter Island should, by all means, have had the same effect on me, but one key detail got in the way: the way the film was advertised.
For a basic plot summary, this film opens with a missing-persons investigation on Shutter Island, which houses the most dangerous mental asylum in the world. Detective Teddy Daniels (Leonardo DiCaprio) leads the investigation, and begins to discover that there is a lot more to Shutter Island than what meets the eye. I can't tell you any more out of fear of loosing major spoilers.
In terms of overall plot and acting, this film is excellent in nearly every sense. The mood is creepy, the acting is competent, and the plot throws you for multiple loops along the way before going for the KO in the final minutes. It is also one of those movies where it takes a little bit of time for all the themes to sink in. About an hour after viewing (or once my mind had finished sifting through things), I actually appreciated it more than while the credits were rolling.
However, the major problem with this film lies (sadly) in the way it was advertised. While watching those thriller classics I listed in the opening, I had absolutely no idea they would end with a huge twist, thus giving it all the more punch when it did occur. Shutter Island, though, was advertised as having "the biggest mind-blowing ending ever" (or something to that extent), and thus during the entire viewing I was guessing at what could REALLY be going on. Thus, while the ending was still shocking, it was already one of the many possible conclusions running through my head while the DVD was spinning, leading to less of a surprise. Perhaps I was just smart enough to figure things out, but I doubt it (!). I'm guessing that many attentive viewers went in with the same thought-processes as me, and maybe found themselves a bit underwhelmed by the ending for the same reason.
Thus, while Shutter Island is still an excellent addition to the "Thriller" genre, I would have appreciated it if they would have advertised it as a straight-forward cop drama, THEN thrown in the twist. Of course, the marketing crew likely played up the surprise ending to get butts in the seats, but for those thinking-viewers among us, it kind of cheapens the experience.
Update (7/1/17): After a recent re-watch of "Shutter Island", I moved it from 7 stars to 9 stars. For whatever reason, this was a movie almost solely advertised on the premise of its "tricky ending", and thus my first viewing of it came through that lens (I was constantly trying to out- guess the proceedings). "Shutter Island" is so much deeper and more nuanced than that, though, and a viewing without the hype helps that tremendously. This really is an excellent film no matter how one slices it.