Innovation is hard to come by. While new consoles must be credited with the few innovations that have arrived (Grand Theft Auto III wouldn't have been possible on a console before PlayStation 2), the majority of games only benefit from increased realism. Even Nintendo Wii, which has led to advancements with Mario and Metroid and innovations with Wii Sports and Wii Fit, is typically reduced to a console that makes tired gaming experiences shakable.

This makes a game like Ninja Gaiden: Dragon Sword doubly sweet. First it's a solid action game that re-creates the console experience for unrelenting bliss. Second, and more significantly, Dragon Sword is a game that couldn't have been made for any system except the Nintendo DS. Its controls were built around the DS's touch mechanics in the same way Nintendo reinvigorated the Legend of Zelda series last fall. But it does not feel like a Zelda game, or like any other touch-based title you've ever played. This is pure action, pure excitement – 100% pure Ninja Gaiden.

A Ninja With Stylus

Factory workers aren't the only ones lining up at the unemployment office – just last week I spotted console and handheld D-pads begging for work. The DS D-pad was at the head of the line shouting, "I work just as hard as the touch screen! Honest!"

In Dragon Sword, you won't use the D-pad or face buttons for anything except blocking. All attacks and character movement is performed with the touch screen. You can use a stylus but a thumb works just as well, thanks entirely to the game's ultra-intuitive controls. Movement is the same as Zelda: touch the screen and Ryu will run in that direction. Jumping is as easy as a quick upward scratch; to attack from the air, scratch left or right for a flying strike, or scratch down to slam straight down. Ninja stars and arrows are fired by tapping (not scratching) any part of the screen. Basic, combo-friendly attacks are executed with a simple scratch over the foe's body. Repeat the scratch (lift your finger or stylus every time) to slash your enemy to death. Once a special scroll has been acquired, keep your stylus planted while scratching and Ryu will perform a multi-hit, multi-enemy projectile assault.

This gameplay style is not only fun and polished (in two words: near-flawless), but it also changes the way you'll look at Ninja Gaiden. Underneath the controls is a bit of an Onimusha knock-off. But it comes off as something far greater than a clone – all things likely, most gamers won't make the connection. They'll be too busy fighting the hordes of ninjas and monstrous bosses to think about anything else.

Your Princess is in Another Dungeon

I must admit that I don't remember much about the past Ninja Gaiden storylines. I love the series for its gameplay, not the character interactions. That said, Dragon Sword's story presentation is stellar. In between lengthy bouts of gameplay, the game intersperses short bits of graphic novel beauty. The artwork is gorgeous and serves as an excellent substitute for CG or anime clips.

As Ryu, you will be expected to prevent the Dragon Stones – small fragments of evil power – from falling into the wrong hands. His main mission, however, is to save Momiji, a young woman being held captive by the game's most vicious monsters.

These goals will take you across 13 chapters of aggressive enemy slaughtering. The battle starts at home but quickly escalates to the netherworld, linking Ryu with several locations outside the bounds of the city. In addition to the main quest, you may also enter additional battles in the netherworld. These take place on one small dungeon platform where as many as four enemies attack simultaneously. Dozens must be defeated before these missions are through. If you're a fan of Onimusha, the comparison here will be impossible to avoid – Capcom's series had the exact same thing several years ago. But it's entertaining, challenging, and gives you the chance to obtain additional bits of Essence.

Soul Reaver and Achiever

In the world of Ninja Gaiden, Essence energy balls – which are dropped by slaughtered enemies – work exactly the same as the soul acquisition in Onimusha and Devil May Cry. Yellow is the color you'll see most frequently; its Essence is the same as cash. Use it to buy sword and health upgrades, and to acquire special attacks via Technique and Ninpo scrolls. Blue Essence replenishes health, and Red Essence replenishes your Ninpo attack energy.

Ninpo moves fall under the "Art of" attack lineup. The Art of the Piercing Void scroll temporarily allows you to kill enemies by tapping them. The Art of the Inferno creates a fireball that you can guide across the screen with your stylus. The Art of the Hurricane does the same thing but with the power of wind. There are seven of these in all, including one that harnesses the power of ice and another that uses electricity.

Each Ninpo is useful in battle but may also have an effect on the level. Early on in the game you'll have to light a few torches with The Art of the Inferno; shortly afterwards you'll be taking out flames with The Art of the Hurricane.

Somebody Call Human Resources, This Boss is Killing Me!

An ugly, over-sized beast is waiting to attack at the end of every stage. Visually, their variety is quite extreme – you'll battle dragons, deformed dinosaurs, a two-legged monster with spider claws, and several other oddities you won't find in any other game.

Physically, however, their challenge only appears to be extreme. Bosses have the power to kill in just a few blows. But their defeat is usually caused by one defensive tactic: learn their attack patterns, dodge them, and attack. The first few bosses can be handled pretty quickly. Run up, slash the beast a dozen times and you're done. The latter group of bosses won't allow such an easy attack to occur. Come close and they'll bite Ryu in half; run away and they'll fire projectile attacks. What to do? Dodge all attacks and retaliate with the strongest projectile currently in your arsenal (ninja stars or regular/explosive arrows). Like the Xbox edition, endurance is vital to your success.

Uhh, Done Already?

Innovation often comes at a price: game length. Dragon Sword's bosses are challenging and the whole game is high on replay value. But it won't take you much more than a day to finish.

If length comes first to you, this might be best suited as a rental (assuming it's available). For the rest of us, the replay value is more than enough to substantiate its status as a must-own release.