Much like the first saga, .hack//G.U.'s appeal lies in it's incredible storyline.
Storyline: the .hackers arc was known for it's amazing story but struggled to keep players interested because of it's ultra-repetitive gameplay. .Hack//G.U., for better or worse, still keeps with the trend. G.U. starts 7 years after the events of Kite and Blackrose have ended. After a fire destroyed the servers that held The World R:1, CC Corporation, the company behind The World, decided to recreate the game as The World R:2. This new world is significantly different than the first in several ways, the most notable for the storyline being, the addition of PKing or Player-killing. Basically what this means is, players can now kill other players. After The World R:2 has become overrun by PKers, a 17 year old creates a character called Haseo and is PKed almost immediately. However, he is saved by a mysterious figure known as Ovan. The game then jumps past the events of the TV show, .Hack//Roots (which IMO is necessary to watch to fully understand the game), where Haseo has become a famous PKKer or player killer killer. After chasing after a strange character named Tri-edge, Haseo loses the battle against this character who takes the appearance of Kite from the first game, and returns to level 1. You then begin your journey in The World R:2.
Gameplay: While the gameplay has been made significantly more interesting through battle changes, it is not enough to save GU from being labeled repetitive like the first game. The most notable change in the battle system is that you now actually enter a battle screen to fight. This prevents random monsters walking around from joining in the battle unexpectedly, sometimes causing your death. Next, there is the addition of the skill trigger. Skills have been completely reformatted from the first saga. Instead of skills being attached to your weapon, you now have to increase your weapon level to gain new skills which stay with you forever. As an Adept Rogue (called a multi-weapon in the show), Haseo can equip all different kinds of weapons. For each weapon, Haseo must level up his skill with it and will then gain new skills. Fortunately, there are now more than two different styles of attacks. Every skill has it's own look and feel to it as well as being useful in different situations. The skill trigger allows you quick access to your skills in battle without feeling intrusive. Simply hit R1 and then hit one of the four face buttons to activate your skills. The best addition to the system however, are Avatar battles. It's hard to explain what avatar's are without spoiling the storyline so i'll simply explain the system. You control a huge monster and you fight other huge monsters in a star fox-esque fight arena. Unfortunately, these awesome-feeling battles, often turn out way too easy and simple as all 4 of the battles are very predictable and follow a set pattern.
Graphics: The CG graphics are fantastic and far surpass anything that you saw in the first .hack games. Unfortunately, the graphics in actual gameplay aren't nearly as nice. The cities look nice enough but the area's are all the same rendered textures repeated endlessly. Since most of your time is spent in the area's, this is a definite flaw in the game.
Sound: The music is in the Celtic style like the old games which is really simply a matter of preference. It fits the games theme very well and sounds nice to most people. The voice-overs, on the other hand, are much more mixed. A few of the voices like Haseo and Kuhn are great and seem very into their characters. Others like Ovan just don't fit at all. Ovan is supposed to be this big, hulking, mysterious guy but his voice sounds like he's bored all the time. Finally, some characters like Gaspard will just annoy the heck out of you the entire game.
Value: The game is much longer than each individual game in the last series but will still be finished in about 30 hours for everything. If you plan on continuing throughout the series, you've got to start with this one but if you are just in it for the single game, don't buy this.