Short answers, pulled from the story.
Capcom released the original game in 2000 for arcades using Sega NAOMI hardware. This specific machine powered the initial arcade experience before a port arrived on the Dreamcast console.
The game introduced a unique rating system called ratio ranging from one to four. Teams could contain up to four fighters but their combined ratios could not exceed four total points.
Hiraki created pixel art for Kyo Kusanagi after leaving SNK years earlier. Capcom asked Hiraki to return specifically for this crossover project.
GameSpot named the Dreamcast version Best Fighting Game for 2000. Mixed or average ratings applied to the PlayStation Pro edition based on technical constraints.
Famitsu scored both versions thirty out of forty in Japan. Edge awarded the Japanese import eight out of ten as well.