Shinobi III: Return of the Ninja Master

I remember that I played this game, I was 13-14 yo or something. There was a local gaming shop in our neighborhood. I was looking for a new game for my Sega Mega Drive and went there. Asked for a dope game. The owner of the shop said to me "Yeah, there is a game, Shinobi but it's so hard for you mate. It's more like adults can play and finish it". Well, great challenge for me! I said "ok, give me that", bought that game and came home. The next day, took the game with me and went to shop again. He said to me "you see, it's hard isn't it?". I said "Sir, the last boss was not that hard actually. You can beat him when he's sending you asteroids... bla bla..." He was looking at me like "wtf, this kid is something else".. Ahh good old days!