Jak 2 really takes the game to a whole new lvl. With the addition of guns and dark powers it makes the game far more enjoyable and intrestinly different from the first game.However the guns mean there are harder enemies with better weapons. It also adds to the difficultly of the game, many people I have talked to either found it frustrating or a good challenge.
For instance there are a couple of lvls that can be beaten in about a half hour or so, but some you need to come back to again and again to complete or having to do other missions to get upgrades on the guns or better weapons to attack with.
Overall i give this game a 9 out of ten, it is a very good game but some of the levels are too hard to do.