Snake's Revenge on NES
i really didn't really care about the story and the only thing that kept me playing this game was the music and the atmosphere.
Those first two Metal Gears were some pretty hard games from what remember. I think I got to the end of the first one.
Actually all of those NES titles were pretty friggin' brutal.
I beat the first Metal Gear. Still remember lobbing ROCKETS at the final boss who was just a human with tons of health :D.