This set of games, which is now natively available for Linux, is built on a highly realistic physics engine. For example, in order to open a door, you have to turn the knob with the mouse. You can grab and throw almost anything from the environment, and it will fly and fall as in the real world.
The environments of these games are spooky underground spaces and corridors. Players are challenged to survive in a shadowy world dominated by horrific creatures.
The game set is available for the reduced price of $5 until the Monday morning, July 20th, at the Penumbra website.