This movie (is made to) look like a montage of retrieved tapes from the camera's brought to the moon in 1972. This means that the camera isn't always steady (like in Cloverfield) and that the quality is a bit bad with static sometimes but it is made to look that way. I think it only help's in getting into the old feeling of the movie.
The first part of the movie looks pretty much like a documentary about going to the moon, but hey, what would you expect. I thought it actually was a bit educating. After that some unexpected things (for the astronauts) start to happen and then the weird things begin. The camera quality and way of filming really helps in feeling the fear of the astronauts.
I read somewhere the last 10 minutes of this movie would be really shocking. Well this actually started the last 15 minutes of the film, with in the beginning the scene's of terror really build op good, then it dies out (probably because I don't thought of the inhumane but necessary message the astronauts get as really shocking, it just seemed logic to me:) ) and then the last 8 minutes the terror gets back but unlike in the beginning of the last 15 minutes, now the scene's last a bit to long, but they are still very nice and frightening.
Overall: a bit weird but nice movie, although i think you must be into the "going to the moon in the 70's" theme to really like it.(like I did)