This is a slow-moving film, without any real gore or jump scares, so it might not appeal to all horror enthusiasts, but I really enjoyed it.
The creepiness comes from it's simple concept: put two characters who are strangers to one another in a small space, (a rundown mobile home) and let them interact, while a vicious thunderstorm rages outside. Almost immediately you know both of them are hiding something, but what..?
Add in some atmospheric sound effects, and a power outage, and the creep factor grows.
I kind of saw the ending coming halfway through the movie, but it didn't dampen my enjoyment of it.
I definitely recommend this claustrophobic little Australian movie!