Given the similarities between Amnesia: The Dark Descent
and games from the Penumbra
series, it should be safe to say that if you've liked one, you'll love the other. For those who have not experienced either, many of the objects in the environment are fully interactable, which allows not only for physics-based puzzles to solve but also allows for access to otherwise unattainable parts of the game (one example may be stacking boxes to reach a higher place).
At first glance, the game's graphics may not be the most appealing, and with the gameplay focused more on exploration than combat, Amnesia will certainly not appeal to everyone. However, if you can find a dark room and a good set of headphones to isolate yourself from other distractions, Amnesia: The Dark Descent will certainly play with your emotions in a dark way.