Street Fighter Zero is the first SF game of the Zero series that has been released on the Saturn. The game comes with 3 different modes (Arcade, Versus and Training) and you can choose between 10 different warriors (Ryu, Chun-li, Nash, Ken, Guy, Birdie, Sodom, Adon, Rose and Sagat). One mode (Dramatic Battle Mode then Team Battle Mode) and 3 more warriors (Gouki, Dan and Vega) can be unlocked.
During your battles, you can use super combos according to the level reached by your super bar. This is something not available in the Street Fighter 2 game.
Street Fighter Zero is a really good game by Capcom but it is not the best of the Zero series.