On Tuesday, thechineseroom and Robert Briscoe released their collaborative project, Dear Esther. Originally released as a Source engine mod, Briscoe (a former professional level designer and environment artist at DICE, most known for working on Mirror's Edge) teamed up with the mod's creator to revamp the game's visuals and polish up the presentation. The result is one of the most beautiful and immersive non-games you'll ever play. There's no real "gameplay", per se. All you can do is walk and look around. But the environments are brilliantly atmospheric, the story is intriguing, the soundtrack is fitting, and the narration is top-notch. I played through it this afternoon and thoroughly enjoyed the experience. It's not long, but it's only $10 on Steam, so head over to the Steam page, check out the trailer and screenshots (they're beautiful), and decide if it's worth dropping your hard-earned dollars on. I certainly recommend it.
(Note: currently, it's only available for PC, but a Mac port is in development.)