Penumbra: Overture is a first person action/adventure game from Frictional Games and Strategy First. You play as an individual named Phillip, who has received a letter from his deceased father, asking him to destroy a set of notes. Instead of doing so, he reads the notes, and travels to an abandoned iron mine in Greenland to follow the clues in the notes. Penumbra: Overture has a physics based engine, and features lots of sophisticated physics-based puzzles, much more so than in Half-Life 2. Nearly every object can be grabbed, pushed, pulled, dragged, thrown, and/or otherwise manipulated.