NFS:UC is another game in the NFS franchise, and features some pretty good police chase mechanics (evolved somewhat from NFS: Most Wanted) and some pretty high production value live action videos to set the scene, starring Maggie Q as your "handler", Chasey Lynn. You're going undercover by infiltrating a bunch of street racers who's obviously also up to no good. However, your "boss" may be up to no good herself... The cities are large, roads are wide, and there are plenty of chase-breakers as well as shortcuts and whatnot. There are 4 classes of cars, from regualr sports to superexotics, and 3 levels of upgrades for each. There are variety of races, from simple circuit to highway battle (get away from the other driver once you're in the lead), from knockout (last place is eliminated) to eliimination (crash target until he's disabled), from timed delivery (take this hot car to destination, no cops!) to cop challenges (take out 5 cop cars then escape), there are a variety of missions to accomplish, using wide variety of cars, all over the major areas of this city.
While the production values are high, and chases can get exciting, the videos come out as a bit... hokey, and the final battle is quite lame. Some of the missions are freaking impossible by game's end as the cars are driving insanely fast, almost beyond human reflexes. Graphics are decent but not spectacular as this is an older game.
All in all, NFS:UC is not quite as good as the original Most Wanted, but the new mission and race types are welcomed. The subsequent iterations, such as Hot Pursuit (3) and "The Run" attempt to capture the magic, but you'll have to read those reviews elsewhere.