Great acting. The plot and story were original despite the slight thematic ripoff of "A Quiet Place". The cinematography was excellent, and it tied the suspense to the audience. The time management was a problem though.
Unnecessary scenes, long pauses, and slow dialogue that could have been used to progress the story killed not only opportunities for more suspense but also any hopes of a resolution. "Bird Box" proves that a happy ending is joyless when the story answers absolutely none of the audience's questions.