14 DAY TRIAL // Forget the introduction. I'll get right on it. The game looks tremendously better on the PS3. Footage over at Gamevideos clearly shows what was improved comparing to the Xbox version and that is...everything. Lighting is better, color beyond imagination, 60 fps, I couldn't tell any difference about the sound though I guess developers made some improvements there too. Check out the movement of falling leaves, with the PS3 version. Not saying that the Xbox version sucks, but a game such as Ninja Gaiden Sigma is the perfect example of the PlayStation3's capabilities, mainly regarding visuals.
In case you didn't know, the game has some history. The original Ninja Gaiden was a NES platformer. The game had two more sequels on the same platform, later (1996) becoming a SNES collection called Ninja Gaiden Trilogy (obviously), featuring all three games. There were slight differences between the Japanese, American and European versions of the game.
As for the Xbox Ninja Gaiden series, it was revived after several years with the 2004 release of Ninja Gaiden for the Xbox. It was developed over five years by developers Tomonobu Itagaki and Team Ninja. It had tremendous success. After that, an upgraded edition with new content, modes and features came out the following year under the name Ninja Gaiden Black. And something to surprise you a bit, the main character, Ryu Hayabusa, is also a main character in the Team Ninja's Dead or Alive fighting game series.
The game had great visuals then, when it was ported to the Xbox, so just imagine what it looks like today, on the PS3. No, better yet don't imagine. See the in-game comparison footage of the two versions and you'll see what I mean.