Need for Speed UG 2 offers a lot of new features that were missing in Need for Speed Underground.
I did like how you could participate in street races whenever you wanted, but since it was a free reom, I wish they would have gotten rid of closed tracks and let you take whatever route you wanted. They also had those races where you just go behind a car and press a button to race them. I thought this was pretty cool, but I hated when I would pass a car and it would still say I was losing the race. They kind of stole the idea from Midnight Club too. They also took Burnout's idea where the nitrous is charged when you get a near miss or get some air off a jump, but this feature worked well in the game.
As far as the graphics, the cars looked really good, but some of the environments looked plain and could have been detailed better. The nitrous effects were really good, just as in the first NFSU game. Overall, Underground 2 was an improvement from the first, but I wish they would have worked on the new improvements more than they worked on improving all of the good things the game already had.