"Amnesia: The Dark Descent," "Dead Space," "Slender" and "Silent Hill 3" are all good horror games according to the list of Scariest Games Ever by T3. These games may not be appropriate for younger players.
In "Amnesia: The Dark Descent," the player plays as an amnesiac named Daniel in the year 1839, who wakes up remembering very little and finding a letter from himself telling him to kill the baron of the castle. The player must hide from monsters as there is no combat option. "Dead Space" features a future in which humans go to other planets to harvest resources, and the player's character is a crew member investigating a mysterious planet on which the mining ship goes dark.
The first-person survival game "Slender" takes the player through a dark forest to find eight notes that involve the urban legend Slenderman. "Silent Hill 3" tells the story of Heather 10 years after the events of the first game in which her father defeats the god of an evil cult in a fog-shrouded place called Silent Hill. Heather must now discover why the cult is following her and learn the truth about her adopted father. The game includes puzzles, exploration and hand-to-hand combat.