penumbra series order

welcome to the official penumbra series website. penumbra is a first person horror adventure series for windows, mac os x and linux. featuring a unique physics based interaction system, allowing the player to interact with the environment in a new and detailed fashion. the game has received a lot of positive reviews for it's atmosphere, audio and story. the series consists of penumbra: overture, penumbra: black plague and its expansion penumbra: requiem. demos are available and the whole series sells for $20.