Back on the PS2, Shinobi was one of the most infamous titles. After trying to go the same route of Ninja Gaiden, the game was greatly despised for difficulty. However, it would seem that this title is back to terrify gamers again.
You can currently purchase the title on the European PSN, for 10 euros or 8 pounds. Overall not a bad value for this classic. No word on a US release, but it seems more than likely sometime in the future.