This movie is a great mystery to sit down and watch for hours.  It's engaging, tense, and thrilling. The acting is great (coming from a bunch of big stars, too) and the imposing nature of the island is very creepy. Like most mysteries, though, it can be a bit boring to watch twice. There are few movies that can escape this dilemma, as the entertainment comes from the audience not knowing the answer to all the questions. Once they know, they rarely forget. It's why mystery films almost never get rebooted, and why this movie's score isn't higher. Anyway, on first viewing, this film is simply great. Almost nothing in it detracts from the experience, and I highly recommend it.