An excellent game if you haven't played Call of Duty 4 yet.
The parts that truly sets itself apart from most first person shooters is the duck and cover mechanism and how you can open the door from the side and throw in a grenade of your choice into the room without exposing yourself to the line of fire.
However the voice acting is at times lacking and of course the graphics just isn't the same if you've feasted your eyes in games like Crysis and Call of Duty 4. It also runs rather sluggish at full resolution and effects in comparison to Call of Duty 4, which really shows how optimized the COD4 engine is.
Overall, it is a good game and I don't regret playing it and finishing it. It was surely time well spent. However, if you have the option, play Las Vegas first before playing the newer games with the fancier voice acting, storyline, and better graphics.