Ryan Reynolds in a Box

Recently I watched the movie called Buried. It has Ryan Reynolds in it. Now you know why I watched it.
So in this movie, Ryan Reynolds is in a wooden coffin buried underground. And that's the movie.
Literally.
The whole entire movie takes place in his box. At the beginning I kept waiting for it to cut to a different scene. In a different setting. But nope, just Ryan in the box. The whole movie. From beginning to end. A box. With Ryan in it.
So I didn't like this movie too much. I got bored! I didn't even understand why he was buried alive and who did it. I think it is explained in the movie, but not very well. And I'm claustrophobic, so this movie made me creeped out in a way that's not enjoyable at all. It's not like the fun adrenaline scary feeling you get from horror movies. I was disappointed with this movie :(