Shinobi is an arcade game created by SEGA in 1987, ported almost immediately to the Master System and later to many other platforms.
In the game, you control a ninja ("shinobi" means "ninja," by the way) who has to fight against an evil terrorist organization called Zeed. You have your faithful shurikens at your disposal, but you can upgrade your weapons: you will find a katana (sword) or a gun during the game. And, of course, being a martial arts expert, you have punches and kicks. But most importantly, you have some special moves called "ninja magic," which are almost indispensable when facing big bosses.
Shinobi was a great success, so it's unsurprising that SEGA released a sequel called The Revenge of Shinobi for the Genesis/Mega Drive two years later. There was also a third chapter, called Shinobi III: Return of the Ninja Master, released in 1993.
But before talking about the sequel, better to play the first game. For all the ones that never tried the original Shinobi, we prepared for you the Master System version. This version, developed directly by SEGA, is often considered the best incarnation of this game, even superior to the arcade one. Anyway, for a retro-computer experience, you can find the Amstrad CPC version too. Since we love you, we avoid publishing the Amiga port, which is terrible. Have fun!