Fans of the series will find a lot to enjoy, while new players may find the game difficult and frustrating.
The story, such as it is, starts with a bang. Sonia, a blond and busty special agent, is searching for Ryu Hayabusa, master ninja and member of the Dragon Ninja Clan sworn to protect the world from evil. It seems there is a plot underway to release the Archfiend, and Sonia needs Ryu to put an end to it. The story progresses from there, with the Black Spider Ninja Clan and monstrous minions of the archfiend one step ahead of Ryu all the way.
But the story is merely an excuse to slaughter hordes of bad guys, and in this area the game excels. Anybody familiar with the original Ninja Gaiden will be instantly familiar with the controls: X initiates a quick attack, Y deals out a strong attack, and pressing these buttons in succession creates combos that will slice and dice your opponents with style. Each weapon that you collect (eight in total) has a unique collection of combos that can be performed. You can still perform Ultimate Techniques by holding Y, which will decimate nearby opponents. New to the series, your attacks now have the ability to dismember your opponents, removing an arm, leg, or head. If you remove an arm or leg, the enemy will continue to fight, but you can deal with them quickly with an Obliteration Technique: press Y near a de-limbed opponent and the camera will zoom in to watch Ryu completely dismember the wounded creature. While looking extremely cool, it also provides a brief, and often needed, respite from the action. You will need these short breaks, as the game bombards you with dozens of opponents, attacking simultaneously from all directions. You will take a lot of damage in this game, and to compensate a new health system has been implemented. You will take damage as normal, but once a battle is over your health will regenerate. However, the end of your health bar will fill red, and this permanent damage will not regenerate; the only way to complete refill your health bar is to find a save point or use a health item. The new system strikes a good balance between maintaining the challenge of the battles and cutting you a little slack by automatically healing you.
Ryu will have a lot more options for dealing damage to the creatures he faces. The different melee weapons offer differing speeds of attack, levels of damage dealt, and combos. The different weapons offer advantages in different situations, assuring that the player will make use of at least some of the different weapons instead of simply playing through with the beginning Dragon Sword (although that is certainly possible). All melee weapons can be upgraded through Muramasa's blacksmith shop, where you can also buy health and magic items with the essence collected from slain enemies. In addition to the different melee weapons, you will also receive ranged weapons. Some enemies can only be defeated with these ranged weapons. Unfortunately, the frustrating control scheme make defeating those creatures especially difficult, and it brings the quick pace of the game to a screeching halt. Rounding out Ryu's offensive abilities are Ninpo, magic spells that can also be upgraded throughout the course of the game.
While progressing through the game, you will encounter Tests of Valor. These side missions are battlegrounds in which Ryu fights a string of opponents. These tests are separate from the storyline and are not required to complete the game, but feature nice rewards, adding to the overall length of the game.
Ninja Gaiden was famous for its level of challenge, and the sequel retains the challenge of the original. Veterans of the series will want to begin on the Path of the Warrior difficulty, but new players now have the option of starting on the Path of the Acolyte, a lower difficulty that will help ease the new player into the game. Once you complete Path of the Warrior, you open up the more difficult Path of the Mentor, and completing that opens the final difficulty, Path of the Master Ninja. You can also play a New Game+ on any difficulty that you complete; this new game will allow you to begin the game at the same difficulty level while retaining the weapons you earned during the previous play through, albeit reset to level one. The multiple difficulties add to the game's replayability, but seeing as there is no multi-player, the multiple difficulties is the only replayability the game offers.
In Ninja Gaiden II, your opponents may not be as smart as in the original, but they will overwhelm you with sheer numbers. You will encounter werewolves with unblockable attacks, ninjas that fire rockets, and the dreaded spider ninjas that throw incendiary shurikens. These opponents are relentless, never backing off, always attacking. You will find yourself being attacked, and often killed, from off-screen. Creatures throw projectiles and grab you unexpectedly quite often. Although this demands you be constantly aware of your environment, these attacks feel more cheap and frustrating than challenging.
Adding to the frustration is the weak camera, a consistent flaw of the series. Not only is it difficult to control, you will often find it trapped behind a wall or a large creature, completely blinding you. You can quickly rotate the camera, but considering how aggressive your opponents are, you could be dead by the time you regain control of the camera. The camera offers even less control during boss fights, locking your view onto the boss. Although this often makes sense, sometimes you will encounter a boss along with several minions, and the minions will constantly attack from off-screen. An improved camera could greatly decrease the frustration. You can increase the speed that the camera moves, which slightly improves a bad situation.
It's too bad the camera is so difficult to use, because the graphics are often beautiful. Ryu is especially highly detailed. He moves quickly and fluidly, and the lights reflect perfectly off his clothing. The creatures are also inventive and attractive. The gore has been considerably increased since the original Ninja Gaiden. Each slash of your weapon sprays blood into the air, coating the floors and walls. Severed limbs and heads litter the environments. Unfortunately, the environments are not as attractive as the characters. The textures are flat, ugly, and poorly lit. In a lot of ways, the game looks like a last generation title. Sound is well done, with weapons clanging together believably, and steel slicing flesh with just the right amount of gooiness.
Fans of the series will find a lot to enjoy in Ninja Gaiden II. Although the Path of the Acolyte offers an option to the new player, many players will find the difficult camera and often cheap opponents frustrating, and the lack of multi-player severely hampers the game's replayability.