Short answers, pulled from the story.
Production for Street Fighter Alpha began in October 1994 following the release of Darkstalkers: The Night Warriors. Capcom gave its development team only three months to build a game from scratch, yet they took six months to finish it.
Developers initially built the game for the older CPS-1 hardware to utilize leftover stock and later developed a version for the newer CPS-2 system when Capcom held a large supply of those chips as well. Both versions were created simultaneously with distinct differences between them including different soundtracks and sound effects.
Akuma returns from Super Street Fighter II Turbo as a secret final boss only after meeting specific in-game requirements while Dan challenges players if certain conditions are met during gameplay. All three secret characters can be selected by inputting specific codes into the system.
The PlayStation version received re-release via PlayStation Network on the 14th of August 2008 in North America. A Windows PC version based on the PlayStation build launched in 1998 and Crawfish Interactive converted a Game Boy Color version released in 1999 featuring downscaled graphics and sound.
Game Machine listed Street Fighter Zero as the second most successful arcade game of July 1995 in Japan. It became the second highest-grossing arcade game of that year below Virtua Fighter 2.