Hidden is one of those movies that has a lot of promise, but doesn't deliver like it should.
The movie starts off well, with a well shot sequence of the characters scrambling through the forest. The early movie also does a good job of presenting pieces of information through character dialogue that the viewer has to add together.
Problems occur as the movie progresses. The pacing remains the same throughout the movie rather than picking up towards the movies climax, so the end product feels monotonous. None of the characters are particularly appealing. Elements go unexplained. The effects shots, although practical and done mainly through a variety of camera techniques, are overdone and cartoonish. The movie makes good use of a variety of shots and camera angles, but these are introduced almost immediately, there's nothing kept for the end of the movie to make it stand out. At one point almost all that can be heard is the sound of wind rushing over a microphone which, although it's supposed to add to the drama of the scene, is just distracting.
Hidden is based around a good (although somewhat familiar) idea. The problem is in the execution. The fact that this is the first large-scale production for the director shows.