All the actors do a nice job with their roles. Teresa Palmer is beautiful and brings a note of vulnerability to the movie. Stephen Moyer's character is the most dynamic, as he makes Andrew's agoraphobia believable. Nate Jones provides most of the movie's excitement, but at times his character is a bit over the top.
Restraint is the best thriller that I've seen since Awake. It's a perfect example of how to keep the audience engaged with twists and turns without making the movie seem unbelievable.
I didn't really like the ending, but that seems to happen a lot...