A gang. A tribe. A family, leaderless and lost behind enemy lines must fight their way back to the safety of their home turf before sunrise. A simple premise makes for one of the best (and most) eighties movies ever made. This was back before New York was an overpriced tourist trap. This New York was gritty, dangerous and dirty place where the police feared to tread. Where a gang of baseball welding psychopaths are the MOST F*CKING TERRIFYING THINGS YOU'LL EVER SEE and the presence of a single gun is enough to throw off the entire balance of power.
I use the word tribal because the gangs are groups of young men and women who band together to protect themselves and their neighborhoods while dressed in matching outfits and living by various codes of honour. The only real crimes they are guilty of are some really awful graffiti tags and a lot of bare knuckle rumbles.
Its a fantasy film, though it is set in a 'modern' city, complete with Warrior Codes and matching uniforms. I have always thought it would make a fantastic roleplaying game on its own, or adapted to pretty much any setting (Shadowrun .. definitely Shadowrun).