Amnesia: The Dark Descent is a cross platform survival horror game that plays in the first-person perspective.
The gameplay consists of exploring a castle trying to regain ones memory in game. There are many physics based puzzles that need solved as well as stealth tactics that have to be used while exploring. During the game the player not only has to keep an eye on their health (as there are monsters in the game) but also keep up on their sanity meter as to not go completely insane.
Pro Incredible use of sound effects
As has been mentioned, the atmosphere is incredible, and I was scared out of my mind the whole time. There's mostly silence. A floorboard creaks, a chain rattles, the shuffling of your feet on the floor, it all serves to take your experience to new, terrifying heights.
Pro Immersive puzzle solving
Amnesia offers immersive puzzles to the player by creating interaction that comes natural to the player. When a door needs opened, the player must pull their mouse towards them to actually open the door, same goes for drawers as well. It is through these interactions that the player can feel as if they are actually manipulating these objects instead of just pointing and clicking like so many other puzzle games.
Pro Tons of extra stories
Users can download and install mods/stories created by other users, which can extend the gameplay of the game by quite a lot. Being that these are custom stories, being able to find one that appeals to the player should be pretty simple enough. A good comparison of the top available stories can be found here.
Pro Excellent, unnerving atmosphere
Much of the game is inspired by Lovecraftian horror wherein the player is constantly assaulted with their sanity being eroded as they try to regain their memories. Monster lurk within the game that are quite frightening and the whole game is sparsely lit with constant sounds surrounding them that could be eluding to their next encounter.