One of the particular strengths of Penumbra is the physics engine and the innovative gameplay, where the player interacts directly with his environment by grabbing objects and moved.
In this way, obstacles to overcome and enemies are avoided.
While one normally has at least one gun in the most even halfway comparable games, the player has to make do with Penumbra with a flashlight, a glow stick and occasionally found tools. Otherwise, the only way to escape the sometimes quite common opponents is, sneak, hide and barricade. Again, attention was paid to realism. Although a barricade of cargo pallets and stacked barrels holds a door closed quite reliable, but if you attention from whatever is on the other side pulls up, keeps them a determined attack was not.
The puzzles are well thought out and realistic, all solutions can be found quite good, if you go carefully through the game.
The plot is engrossing and the game is suitable atmospherically conveyed (the players know the first pass, no more than the game character, practically nothing ...)
Overall, a highly recommended game, especially for people who are looking in the time of Doom 3 and Half Life 2 times an intelligent horror game :)