I've played some Half-Life 2, and I have to say that it fails to live up to its reputation. While it does have a good physics engine, that doesn't make a good game. The AI, from what I've seen, is very disappointing. The Combine soldiers stand there, and they try to shoot you.
Also, the seemingly endless boat ride segment is torment in video game form. I don't know why they thought riding around in a boat and solving random puzzles was the peak of entertainment.
Also, what FPS comes out without a multiplayer mode?
The physics engine is rather neat though. If you want to stack objects, but hate lifting things, this would be the game to play.
P.S. The title is literal. Apparently, Gordon Freeman is bought and sold like meat.
P.P.S. "We're going to take your guns. Except your magic gun. We'll supercharge that, then give it back." What's up with that?