Stars operating at the level of Halle Berry and Penelope Cruz are bound to disappoint critics along the way, especially when the critics are just waiting for some sign of weakness upon which to feed. While there is nothing wrong with any of the acting in this film - these are not the kinds of roles Oscar winners and nominees are expected to indulge in.
What's more, Berry and Cruz signed onto a film made by a production team which has typecast itself with some fairly disappointing ghost stories / horror films involving big-names in the recent past.
Finally, this is one of those cases where the trailer was so good that the film could not possibly follow it.
If you approach this film without expectations, and with an open mind, you will be entertained. It's a tight, disturbing psychological/supernatural thriller which, though a little predictable at times, nevertheless offers some frightening imagery and a few good solid scares. That said, this is not a film for people who have trouble paying attention or for people who need straightforward answers. If you don't really pay attention to what is going on in this film, you could easily dismiss it as a more adult version of Sixth Sense or just another dumb ghost story. This film deserves more credit than that.
Personally, I don't think it's a ghost story at all- but that is a question best left open.
I have seen a number of films by this team - House on Haunted Hill, 13 Ghosts and Ghost Ship. Of these, I found 13 Ghosts and the House on Haunted Hill to be entertaining, but not very intelligent. Ghost Ship was tremendously disappointing - even Gabriel Byrne could not save that film. Gothika is easily the best of the lot, and also the darkest. The film is shot in dark blue, black and gray tones, and the use of lighting is nothing short of artistic. Despite the cliché title, the occasional plot clichés, and all the negative publicity generated by critics, I found this film to be surprisingly entertaining, intelligent, and disturbing.
Most of the 'plot holes' cited by some reviewers here on IMDb are more likely gaps in the attention spans of the viewers themselves or intentional ambiguities designed by the production team. This, unlike any of this team's previous work, does not provide unambiguous explanations.
Cruz and Berry are, respectively, patient and psychiatrist in a high security prison for the criminally insane. The Gothic environment of this facility is not meant to be realistic, but surreal, and the effect works. From the first time you see the place, you question its own reality. The film constantly manipulates mood through cinematographic techniques like this.
Shortly after the film opens, Berry finds herself experiencing what some of her allegedly delusional patients talk to her about. Robert Downey's portrayal of her friend and, now, therapist, is uneven, but satisfactory.
To describe the rest of the plot would require spoilers, so I won't bother. Suffice to say that even the occasional predictability of this film did not detract from my enjoyment of it.
The film uses just enough ambiguity to permit the audience to wonder whether what they are seeing is really happening or whether it is a product of our protagonist's subconscious mind. And then, in the end, the film makes you question whether it matters.