Slow pace in the most part of the movie.

SERIOUSLY. This is what the crap Hollywood still puts out?

I was totally surprised at how great this film.You could feel your paranoia rise as the film went on and as you gradually learned the details of the real situation.

A film with more than the usual spoiler issues. Talking about it in any detail feels akin to handing you a gift-wrapped present and saying, "I hope you like it -- It's a thriller about a diabolical secret experiment."