Are you tired of the same old tropes for side-scrolling beat-em-ups? It's usually either save the girl or save the world, and it's all very serious. River City Girls is a lot more tongue in cheek, as two schoolgirls try to save their boyfriends from being kidnapped by punching and kicking their way through other students, mall cops, and masked wrestlers.
On the surface, River City Girls is remarkably similar to other River City Ransom games. They're more standard beat-em-ups where punching an enemy enough makes them barf money which, in River City Girls, you can spend on new moves and accessories as well as recovery items. You also get to make alliances with enemies that grovel at your feet, giving you an assist that drops in at a push of a button.
River City Girls also has some of the most unique boss fights I've seen in a beat-em-up. Each one has multiple stages with unique attacks, and they escalate in a similar way to Scott Pilgrim's battles against evil exes. They all have awesome boss themes courtesy of "Chipzel", who did the music for most of Terry Cavanagh's games and Octahedron. She seems to crop up a lot in games where I really like the music, which is probably not a coincidence.
(This isn't the only time that WayForward have changed the status quo in a beat-em-up, mind you. They also made the 1980s Saturday morning cartoon fever dream that is Double Dragon Neon.)