Short answers, pulled from the story.
Final Fight is a beat 'em up arcade game developed and published by Capcom, released in 1989. Players control one of three characters - Mike Haggar, Cody Travers, or Guy - fighting through six rounds of Metro City to rescue Haggar's daughter Jessica from the Mad Gear Gang.
Yes. Final Fight began development as a Street Fighter sequel and was shown at trade shows under the working title Street Fighter '89. Capcom's sales division requested a Street Fighter sequel, but the game's genre changed and operators told the team it resembled nothing like Street Fighter, prompting the title change before official release.
Final Fight sold 30,000 arcade units worldwide and became the highest-grossing arcade game of 1990 in Japan according to the annual Gamest charts. In the United States it topped the RePlay charts as the highest-grossing software conversion kit for eight months of 1990, with weekly coin-drop earnings averaging $183.50 per kit during November and December.
The English Super NES version renamed the first two bosses (Damnd became Thrasher, Sodom became Katana), replaced female enemies Poison and Roxy with male characters named Billy and Sid, removed all alcohol references, changed a blood effect to a generic explosion, and lightened the skin tones of some enemy characters.
Seven composers worked on the Final Fight soundtrack: Manami Matsumae, Yoshihiro Sakaguchi, Harumi Fujita, Junko Tamiya, Yasuaki Fujita, Hiromitsu Takaoka, and Yoko Shimomura. Only Sakaguchi was credited in the arcade release; the other six were not publicly confirmed until 2014, when City Connection released the Final Fight Original Sound Collection.
Director Walter Hill's films, particularly Streets of Fire, were a direct influence. Producer K. Tsujimoto instructed designer Akira Nishitani to watch all of Hill's films; the team viewed them simultaneously on three monitors in a Video Materials Room due to time constraints. Les Misérables also influenced the character of Mike Haggar, drawing on Jean Valjean's role as a mayor and devoted father.