Short answers, pulled from the story.
SNK vs. Capcom: The Match of the Millennium was developed by Dimps and published by SNK. Takashi Nishiyama from SNK and Yoshiki Okamoto from Capcom met to discuss the collaborative project that brought together their respective fighting game universes.
SNK vs. Capcom: The Match of the Millennium was released in 1999 for the Neo Geo Pocket Color handheld console. IGN gave the game a perfect 10 out of 10 score on the 5th of January 2000.
SNK vs. Capcom: The Match of the Millennium features 2-fighter tag teams, 3-fighter queue teams, and one-on-one matches. The game also includes an Olympic mode with themed minigames such as blasting Martians and helping Arthur from Ghosts 'n Goblins hop pits.
SNK vs. Capcom: The Match of the Millennium sold 75,000 copies in Japan. It remains the overall best-selling game for the Neo Geo Pocket (+Color) platform in that region.
SNK vs. Capcom: The Match of the Millennium was created to save the struggling Neo Geo Pocket Color handheld console. The project aimed to create compelling content for the system which was facing stiff competition from other handheld systems.