Liam Neeson is a badass. This is evident in a number of films but most notably in Taken. When the trailers for Unknown came out my first thought was that it is Taken 2! Not exactly the right sentiment but it was close. Also, Hitlers in it.
Last thing first: the detective met about 1/3 in is the same actor who plays Hitler in the movie Downfall which I doubt youve actually seen but its likely youve seen one of the (many) Internet meme re-subtitling videos of Hitler being annoyed by _______. Or maybe its just my weird guilty pleasure. Anyway I recognized him way too quickly and it gnawed on me all through the movie, but it was a good kind of gnawing. Comforting.
Its hard to not give away the central twists to this because I think the conceit is very good. The movie kept me guessing for quite a while. Having watched Adjustment Bureau recently my mind was going way off the deep end to reconcile the plot action. Its a lot simpler than it looks. Elegant.
There is really only Liam in this movie. There are a couple other characters but it is mostly following him in a very third-person-limited fashion. I love this style of movie. The parts where it goes 3rd person omniscient are the weakest in my opinion. By staying with Liams limited perspective it makes it much more interesting.
The only other gripe is the ending. Not the climax of the film– they have a few seconds to throw together before the credits and they did it in a way that I associate with a. French films, and now Liam Neeson films: a very saccharine happy ending. At least in Taken it makes sense. In Unknown it seems hastily put together. The helicopter shot of Berlin under the credits was nice.