I'm on chapter 10 or 11, titled TRAPPED. How many chapters are there in the entire game? Anway, its a great game. I find the difficulty on normal to be challenging, and I've died a few times :D . I wish there was some online component, but it probably wouldn't be that good anway. This game reminds me of the Indiana Jones movies, and plays a little like the Indiana Jones game released on the Xbox. I loved that game, although it racked up some mediocre reviews I loved it. If you have a working Xbox try out Indiana Jones and the Emperors Tomb on the box or PS2.
With Uncharted on my mind, I hope the upcoming Indy game plays similar to Uncharted. I've read some articles about its game engine and its physics...it looks amazing.
I'm really dying to play MGS 4, I'll make a video review/my thought's about it when it comes out.