What a great game, let me start out with that. This game has the attention to detail that you would expect from a grand theft game. Some of the things I have noticed are:
-Scratch off tickets
-Taking out cop cars lowers the chance of them getting you, instead of the old ones where they chase you till they can't see you.
-Graphics are amazing for DS, and the PDA menu fits in perfectly with the DS
-More ways to make money other than just robbing places and doing stupid jobs.
The only thing that really bothers me about the game, is once and a while you have to use the stylist. Which isn't all bad for some games, but when you are trying to steal a car and you have to do a screwdriver mini game...it can turn out bad. It can be especially bad if you just bough 4k in heroin and it was a bust by the cops and now you have 3 stars. Think on top of that you have to pick a lock with your stylist. Again the whole stylist thing isn't bad, its just hard to switch back and forth all the time.
Also I did want to mention, in KevinS's review he said the driving hasn't improved since ps1, which is far from true. This game has an angled view so you can see farther in front of you. Yes the targeting can be bad, but it is a far improvement from the PS1 grand thefts.