Creep can't really escape the narrative weakness that many "found footage" films suffer from - the suspension of disbelief required to accept the rationale of the "filmmaker" to carry on filming no matter the way in which the plot develops. That being said, the central conceit actually works quite well here - there is a deep sense of unease that is developed in the film, but the film manages to just about keep the audience on side with the central character's dilemma of conforming to social niceties in the face of an antagonist that he clearly recognises as creepy, but rationalises the behaviour as socially inept rather than dangerous. There are a couple of clever tricks employed in the use of the footage that work really well and the final act and reveal to show how the footage came to be "found" is a nice twist on the usual abrupt finale that most films like this employ.