Remove Mark Duplass from the equation and what you got is a weak found footage film that has trouble justifying why it exists more than anything else. There are genuine moments of honest suspense and disturbing images that linger, but it's a chore to get through. If I wasn't watching this for personal research for other found-footage films for a project I'm working on, I would have probably turned it off halfway.
Although Creep may interestingly only feature 2 characters in this found footage-esque comedy-horror film, it's sadly much more childish than funny or scary. The scares are mainly in the form of only bad, corny jump scares, and the few tense moments are underplayed. A decent twist comes at the hour mark in terms of Josef's intentions, but it isn't as nervewracking as it could be. Creep is a film that doesn't arose.