A teaser trailer has been released for Outlast 2, the sequel to what is regarded as one of the scariest video games ever made. Set for launch in Fall, 2016, developer Red Barrels says the game will have even more surprises than the original, and that the sequel will test players' faith.

The first Outlast was released in 2013 and, while it may have its weaker moments, the game quickly became accepted as one of the most terrifying horror titles ever released. The story follows Miles Upshur, an investigative reporter searching a psychiatric hospital overrun by homicidal inmates as he seeks to uncover the dark secrets it hides. Much like the similarly scary Amnesia, the protagonist in Outlast is incapable of combat; instead, Miles must use the environment to escape or hide from his attackers.

One of the best elements of Outlast is its use of a night vision camera. Because so much of the asylum is covered in almost complete darkness, Miles is regularly forced to use this green-tinted camera mode to get around. But as it drains the (collectable) batteries pretty quickly, players must use the night vision sparingly - which really ramps up the tension. The teaser trailer shows this game mechanic will make a return in the sequel.

Outlast 2 will have a new cast of characters and a new setting. The developers aren't giving much away, but Red Barrels' Phillipe Morin did have this to say about the game: "No conflict is ever black and white. But once the dust has settled, the victors get to decide who was right and who was wrong. Who is good and who is evil. Human nature pushes us to extremes of violence and depravity, which we then justify by divine inspiration and a promise of paradise to come. Horror rises from desperation and blind faith. Outlast 2 will test your faith, pushing players to a place where going mad is the only sane thing to do."

Company co-founder David Chateauneuf told IGN "We have even more surprises and I can't wait to tell you all the ways we're going to make Outlast 2 gamers suffer.

Check out the teaser trailer below. Outlast 2 is expected to be released on the PC, PS4 and Xbox One.