The Penumbra first person horror action-adventure game series just got an expansion pack. Penumbra: Requiem is now available for download at Gamersgate and Direct2Drive for just $9.99. The expansion from developer Frictional Games requires the installation of Penumbra: Black Plague.

In a note on the Frictional Games web site site, the developers state that this expansion concentrates on the physics puzzles and gameplay more than previous installments. According to the site, "Requiem does its best to deliver a nightmarish and feverish atmosphere. Penumbra: Requiem is an attempt to deliver a fresh and rewarding experience and not just some rehash of previous material." While the expansion is for the moment for the Windows platform Macintosh and Linux users will get their own versions soon, according to the web site.