Jak and Daxter is an amazing game, and the sequel, is even better. However, it is very fustrating at times.
Jak II, offers more open world gameplay, this time bringing Jak into the big city! Here you can ride all kinds of vehicles, and even use guns.
The city however looks a little dull, and boring. They could have done better.
The worst part about the game is the diffuculty level. At some points it is literaly impossible. It's one of those games where if you mess up on a level and die, you start all the way at the begining of the level. I found myself very angry at times, when I would get so far, and then start over.
Overall, the game is great, and I would highly suggest getting it, though you might want to rent it before you buy it. It is much different from Jak and Daxter.