The Demo for Macintosh computers from Frictional Games.
Frictional Games has released a demo of the Mac version of Penumbra: Overture.
The demo of Penumbra: Overture gives you a short taste of the full episode. You'll get a chance to play the first couple of levels and tease your brain slightly with a few puzzles as you play around with the advanced physics.
Mac Minimum Requirements:
OS: Mac OS X 10.4 or newer
Disc Space: 300MB free(for demo)
Video Card: Radeon 9600/GeForce 4
(GeForce4MX not supported)