Apollo 18 is the kind of movie that will likely divide audiences the same way The Blair Witch Project did years ago; people either love it or hate it. The comparison is appropriate because without Blair Witch, there would likely be no Apollo 18. The concept of a "found footage" movie is ingenious because it allows the audience to buy into the realism that the filmmakers are attempting to set their story in. The drawback to this is that a portion of the audience doesn't want to buy into the alternate reality of the film and will inevitably call bull after they've seen the film.
Unfortunately, the haters would be justified in this case because Apollo 18 never really delivers. And it really is too bad because the concept is a cool one. Officially, Apollo 17 was the final manned operation to the moon. However, a top secret 18th Apollo mission was planned and executed without the public's knowledge. The astronauts were not told what exactly the purpose of the mission was but after arriving, they figure it out pretty quickly. From there, the movie feels all too familiar and you find yourself guessing what will happen next which tends to inspire boredom.
This isn't the fault of the no-name cast who do the best they can. Ultimately, what's most disappointing about Apollo 18 is that it is poorly executed. As you watch the film, you keep waiting for the payoff and while director Gonzalo López-Gallego does a good job of building the suspense, by the time you get to the big moment, you find yourself saying, "Really? That's it?" The Blair Witch Project worked because it employed the tactic of the-scariest-part-is-what-you-don't-see. In Apollo 18, you do get to see what's scary, but it's kind of a let down. There was the potential to do so much more with this film but that potential is never realized.
Ultimately, Apollo 18 suffers from two major flaws: it's too derivative and while the build up is great, the end doesn't satisfy the viewer. I recommend skipping this one iat the Cinemagics in Hooksett and Merrimack and waiting for DVD if you're still inclined to see it.