- Colbert Bump: The franchise as a whole is gaining one thanks to River City Girls reaching a much larger audience than the relatively niche installments.
- Divorced Installment:
- Renegade was so popular in Europe that the British company Imagine Software developed two direct sequels to this version: Target Renegade and Renegade III: The Final Chapter.
- River City Ransom: Underground takes place in the American urban setting created for the English localization of River City Ransom. Barring a couple of homage, there's little trace of Kunio-kun reference to be found.
- Dolled-Up Installment: The 1990 Game Boy entry, Nekketsu Kōha Kunio-kun: Bangai Rantō Hen, was remade into a Double Dragon game, probably for brand recognition. It's confusingly named "Double Dragon II", even though the gameplay is identical to the Japanese one and, as such, has nothing to do with the Arcade and NES game of the same name.
- No Dub for You: In the reverse of what western fans might expect from a long franchise with several Japan-only titles, River City Girls as an American-made installment features exclusively English voice acting. This is especially bizarre, considering the game, despite not looking it, still takes place in Japan.
- Promoted Fanboy: After the announcement of River City Girls, the twitter user Kay revealed that he's in the game's staff as its lead pixel animator.
- What Could Have Been: As seen at the end of Crash 'n the Boys, Nekketsu Hockey Bu was planned to be released outside of Japan as Crash 'n the Boys: Ice Challenge, but this never made it to the US as the NES was unfortunately approaching the end of its lifespan.
- Wiki Rule: There is a wiki for the series here.
Trivia / Kunio-kun