Where XIII failed, XIII-2 succeeded.
1. Amazing graphic and environmental design that perfectly sets the mood as it should be.
2. More fluid gameplay.
3. Interesting story that draws you in.
4. Monster collection adds personality and customization to your team
5. Not at all linear and provides a good means for exploration.
6. Noel is a very interesting character.
Cons
1. Too many cut scenes.
2. Drawn out beginning.
3. Most battles can be completed by pushing the A/X button repeatedly.
4. The dramatic shift in difficulty from common enemies to bosses is insane and can be overwhelming.
5. There isn't an in-depth back story for Mog.
3. While Lightning was a great heroine for the first game, her sister, Serah, did not at all give off the feel of a hero.
I feel everything here is self explanatory so I'll leave it up to you now.