The movie makes good use of random drops and slides that occur throughout the movie to hint at possible mysteries that might remain unexplained (note that most of these clues don't affect the ending). Some reviews refer to how good of an actor Oscar Isaac is as Professor Marvin Bagwell and how interesting it was that these mysterious slides happened at different points throughout the movie (although most reviewers seemed to prefer it when Bagwell showed up later). Also some reviewers noticed how weird it was that Isaac wouldn't answer questions while performing these