Today's PSN update unleashes both Outlast and Metro: Last Light for free if you're a PS+ subscriber. If you haven't played either, be aware that Outlast is scary enough to make you crap your pants, while Metro is very boring.
At least that's how I feel.
Regardless, they are free, so you may as well try them. Outlast is my my favorite horror game of this gen so I definitely recommend the download!