Game Description:In the fourth installment of the Mega Man Zero series, Neo Arcadia has fallen into the hands of the evil Dr. Weil. Chaos rages through the city. Zero must save the day! Defeat Dr. Weil and restore peace and security to Neo Arcadia. Zero's up against his toughest challenge ever: 16 levels with 16 bosses and 40 different enemies. Thankfully, Zero's got new and powerful tricks up his sleeve. Battle with improved weapons, or seize weapons from enemies you've beaten. Combine stolen parts to make new items and gain added abilities. Adjust the difficulty level using the Weather Changing System to get the most from this exhilarating action-adventure.