Good reflexes are mandatory.

User Rating: 8.4 | Tom Clancy's Rainbow Six 3 XBOX
I just bought this game a little while back and am currently reading the book as well and I will make comparisons along the way. This game is extremely like the book. Not in terms of story but in action. In one part in the book, during an exercise in Hereford, they took down a room in 7 seconds, no different in this. You only get 3 checkpoints in a level which also hads difficulty. If you can't go in a room, identify hostiles, and take them down fast, your screwed. This game also uses rag doll physics but there's not much time to notice them as your rushing into a room trying not to get shot. This is also a gory game as you can shoot a guy and blood will be on the wall behind him.
One thing i found different about the book is coarse language. In the book the people are uncontrollabe with the F word and son of a *****. In the game you don't hear anything like that.
One aspect of the game i find is fun is the weapons load-out screen. You can choose which weapon you wanna go out with into a mission and use. This game also uses stealth, not like splinter cell though. You can't get spotted if you get behind a guy but he can hear you if you step on metal grating or something. This game certainly has better stealth gameplay than a First-Person James Bond game so I enjoy sneaking around.
Overall this game is pretty hard but is a tense action shooter.