Son Son is Capcom's tribute to a Chinese legend called Xiyou Ji, meaning 'Journey to the West', considered to be one of the four classic pieces of Chinese literature. The main character in Xiyou Ji is Sun Wukong, or, when the words are pronounced as if they were Japanese kanji, Son Gokuu (hence the name Son Son).
All of Son Wukong's companions besides Zhu Bajie (Pigsy) are snatched by a demon and it's up to the two of them to chase after the demon and rescue them. The game auto-scrolls with multiple platform "tiers" and the player must switch between them and attack incoming enemies with their weapon. By switching tiers, the player can collect score items.