I'm sure you've already read in Gamespot's review that the game is short. However, if you like a solid samurai action...
The graphics are nice for a Playstation 2 game, higher than Gamespot's rating. The story is pretty run-of-the mill, nothing special. The gameplay breaks down into slow gameplay (kamui) and fast gameplay (regular). Kamui system is pretty cool looking. However, the non-Kamui (regular) combat is pretty uninteresting. You have a set combination you may perform that does not improve as you level up. This aspect could definitely be better.
Hard mode is also available, but the strategy of actually beating hard mode requires more tedious labor than skillful combat.The reward for beating Hard mode is....wait for it....concept art! Yay. [/end sarcasm]
The music, visuals, and overall presentation are very good. Bottom line: buy this game if you're interested in samurai myth and culture, as well as some decent action gameplay.