Narc was a notable arcade release by Williams (design of Mr. Robotron Himself, Eugene Jarvis!) put forth in 1988, and ported to NES by Rare/Acclaim in 1990 (and a whole slew of other devs for other systems).
This title released when NES games were starting to look pretty appealing next to their arcade counterparts, games like Narc swooped down and put them in their place "you STILL cannot look anywhere near this good!" Loaded with digitized graphics and lots of color, not to mention "the ol' ultraviolence," Narc was a beautiful picture of an abysmal urban world spoiled by mayhem and turmoil. With no shortage of hand-held rocket launchers, armed Porsches to run over people with, and exploding body parts. Also, clown rapists. Oh man - Williams bust have been a very interesting studio to work for in the late 1980s..
The game itself wasn't terribly complicated - walk around and either "bust" guys (nonviolent approach) or blow them to Kingdom Come with your arsenal - this game took on the war on drugs in a pretty hilarious fashion.
Ultimately, in spite of my graphics-whorism I never game Narc too much of a go - though it was worth a few credits, the gameplay felt extremely lacking for my tastes and something about the bleakness of it's highly-detailed world was just unsettling to look at. In Narc you are charged with cleaning up the streets, but they just made you realize "wow the world we live in can be - actually, depressingly ugly!"
Likewise, the control scheme was something they hadn't quite nailed. You could walk, shoot, and kneel, but it was hard to know what to do when, at times. It wasn't too bad, but it was never a game like Contra or TMNT where you just felt "instantly connected" with your guy on the screen. I'd feed a couple coins to see the advanced graphics, get my fill and then move on. I think they could have pushed the concept a little further and come up with something much more memorable - still, Narc was enjoyable to play and it deserves it's place in the history of gaming.
Also, the last boss is just.. freakin' weird-o, man.