This is a revision of Revenge of Shinobi, The (USA, Europe). The revision likely involved bug fixes, minor gameplay adjustments, or potential improvements to the graphics or sound.  The core gameplay remained largely the same, but minor changes across different revisions could have affected the overall experience.  The release of revisions is a common practice in game development to address any issues discovered after the initial launch.

Revenge of Shinobi, The (USA, Europe) (Rev A)

Rent a Hero (Japan)