I. Love. This. Game.
Alot of horror games recently have been either not scary enough or just a guided scare tour without any real gameplay.
Five Nights does horror perfectly by putting fear and gameplay on an equal level. There's actually STRATEGY to how you play, and it drums up the fear even more by creating a genuine sense of control and urgency.
Not to mention how they use the jump scares. Many people say that jump scares are cheap, and on many fronts, I would agree, but this game uses them only when you fail, something that YOU are responsible for, not just because the game felt like one should be there. (Though, to be fair, they are used a bit more often later on, but they are kept more subtle.)
It's a bit short (it can take anywhere from 8 hours to 45 minutes to complete), but really, it's worth your $5. Hell, even if you only play the DEMO, it's an awesome experience.
And I'm SO pumped for that 2nd one...