Apollo 18 may wish it was part of the impressive low-tech sci-fi movement arising in films (Sunshine, Monsters, District 9, Another Earth,) but it is not. It’s really just a Blair Witch thing set in space, except that it is better than Blair Witch. They didn’t write enough dialog, or craft the story in an interesting and memorable way, and they rely too heavily on the central gimmick: the entire film is “found footage” from the secret mission. This basically puts a (rather low) ceiling on how good the film can be.
With that said, however, I must remark that they did the gimmick pretty well. They managed to make the footage seem fairly real and spontaneous, and did capture to a decent extent a certain vibe of an “official film record” of the mission. I thought all 3 main actors were really good in their roles, despite the relative lack of dialog. The pacing of the film is decent, and it didn’t devolve too much toward the end, as these things tend to do. With the right expectations, this film is enjoyable, with the caveat that it is a bit depressing in the end, and sort-of leaves a bit of a bad taste.
As a light diversion, if you like gross, creepy sci-fi, and don’t mind hand-held shaky-cam, give Apollo 18 a try. Just don’t expect too much.