Contra (1988): One of the most beloved shooters of the NES era, Contra harbors a not-so-hidden secret: It's ridiculously hard unless you use the so-called Konami Code to give yourself 30 lives. But with the code in place, the difficulty level is relaxed enough to let you enjoy it for the accomplished and polished shooter it is. You (and an optional friend) control Lance and Bill, two soldiers dropped into the jungle to battle the alien menace known as Red Falcon. With its two-player simultaneous action, variety of weapons, and horizontal, vertical and pseudo-3D stages, Contra became the standard by which future platform shooters would be judged. SOURCE: http://allgame.com/
seeGAMEPLAY