Fun Fact: The graphic novel series Scott Pilgrim has several references to River City Ransom.
River City Ransom was a side-scrolling beat-em-up. The game's heroes, Alex and Ryan, had to get across town to save Ryan's girlfriend. Alex and Ryan would fight nine different gangs along the way.
The combat was very similar to the Double Dragon series. Players could jump, and use kicks, punches and dropped weapons to beat up the gang members. The game also incorporated some basic RPG mechanics. Alex and Ryan could loot gang members and use the money to buy books from which they could learn fighting skills, or purchase other items from stores, all of which could increase their stats and ability to fight.
River City Ransom also had a much more open game world than Double Dragon. It was non-linear and had room for exploration. Unfortunately, River City Ransom never really caught on and is considered a hidden gem among NES games.