Saw this last night at a special screening followed by a Q&A with Jesse Eisenberg - I thought it was brilliant and actually NOT predictable as someone else said in the thread.
Jesse actually said one of the reasons he chose to do the movie was because he gets sent a lot of scripts for movies where you can pick out the twists from the first 5 minutes but this was caught him off guard and he also never could've imagined himself in a movie of this genre.