Genji is a good title if you want the next-gen feel or if you like buttion mashing games, but that's about it.
Mostly what you do is run up to an enemy an hit the attack button over and over again. Then when they attack you hit the block button. When you have killed all your enemies you run somewhere else and fight more enemies. It is also difficult to know where to go next, as the game tells you to find something or go somewhere, but just sort of leaves you to do it yourself. I would recommend a walkthrough or else you could spend hours just trying to figure out where to go.
However the game does give you a great feel of the next generation with great graphics and very good sound. These are the highlights of this game. However while this may have been a good game early on to give you the next gen feel, you are probably better off waiting for the releases of similar games such as Heavenly Sword and Devil May Cry 4, which are probably going to be better.
You won't get much value from this game and unless you are a fan of these types of games, you won't like it much. My advice: This game isn't really worth your money, but if you like these types of games you should rent it but do so with caution.