One of the hardest games on the PS3 and it's still fun
A new playable character, Rachel, the demon hunter. A new weapon for Ryu, a set of dual katanas called Dragon's Claw and Tiger's Fang. Three new enemies have been added: MSAT bikers, Mermen, and Ghost Fires. Two new bosses have been added: Gamov and Alternator (an enemy like Dynamo). Some new animations have been added (When performing a "reverse wind technique" backwards Ryu now does a backflip as oppose to a simple roll and certain humanoid enemies have a new staggering animation when hit). Many more save points and shop locations are added into Story Mode. Shaking the SIXAXIS controller will increase the strength of the ninpo being casted.
Also, there were a lot of stuff removed from this Ninja Gaiden game that was in the originally Xbox version. Here are some stuff removed.
The opening introductory movie of the legend between the Dragon Sword and the Dark Dragon Blade. The Movie Theater (this means the player will be unable to view the remaining 480p movies outside of Story Mode). Some encounters, two costumes, and many puzzles. Additional starting weapons on higher difficulties (only in Ninja Gaiden Black). The Armlet of Tranquility, trailing images and light effects from certain power moves, and NES or Arcade versions of Ninja Gaiden previously unlocked as bonuses in the Xbox Ninja Gaiden / Ninja Gaiden Black.
Overall it's a great remake of Ninja Gaiden and you should pick it up! It's $20 too! Great deal!
Overall score: 8.5/10