Ya the classic game by SEGA, Shinobi III is now also available in iTunes for iPod, iPhone and iPad user for US$2.99. The games is playable to 28 stages.
As mention on iTunes :
The games allow you to move like Ninja, with the the D-Pad or Accelerometer controls to run, wall jump, swing and even ride a Jet Ski and stallion! Fight like a Ninja by utilizing shuriken, swords, stage items, and fierce ninja magic to counter Neo Zeed’s forces