Paradox Interactive today announced that Penumbra Collection, a compilation which includes all three Penumbra titles developed by Frictional Games (Penumbra: Overture, Penumbra: Black Plague, and Penumbra: Requiem), has shipped to retail across North America. The Penumbra series features challenging problem solving and survival powered by the unique physics system that allows the gamer to interact with nearly every object. Press 'read more' for details.