GRAW is one of those games that takes a familiar thing and adds its own little twist to things, and does it darn well.
The game is a third person style shooter. It may not be up to par graphically with games like Gears, but it still looks very good, especially for such an early 360 title. The sound is great, with some modern music mixed in at cool points, and cinema quality orchestra pieces at others. The gameplay itself is very well done, immersing you in the battle. The way jammers and such things affect your computer systems is very cool, although it seems unrealistic that it also affects your regular vision as well. What are we doing, looking through a camera? Battles can get pretty intense, with explosions going off and bullets flying in just about every direction possible. I will say it is definitely more realistic than some things. In other words, if you're a run-n-gun sort of person, this game may not be for you.
GRAW may lack a little bit in depth of story, but since when are these games made for the story? It does a great job of sticking you in a situation, if not a full blown war, in the middle of a dense city, and making it a fun trip. I don't have an hour figure, but it will last you long enough (I certainly wasn't saying "dang that was short"). If you enjoy tactical shooters, this game is certainly worth buying.