This has to be my favourite monster film, and probably one of the best hand-held camera films to date. The effects and CGI are superb and the cast, albeit largely unknown actors when this was made, are all brilliant in their roles, each delivering very natural performances. This is a key success to the film, making the hand-held camera style work at its best. Together, these qualities make the film very believable, allowing you to really feel the terror of the situation throughout.