One actor movies

I saw Locke by mere accident and I felt that it was not upto my taste - sorry! On the other hand I was ok with Gravity!

Here is a list of such 'minimal' movies.
http://www.latimes.com/entertainment/movies/moviesnow/la-et-mn-locke-one-actor-movies-gravity-buried-20140425-story.html

Tell me what you think about such movies. Do you like them or hate them?