Just like its predecessor, the game is loosely based on the classic well-known Chinese novel Journey to the West. In this platformer, the players take control of Son Goku who has to rescue his three friends from a mysterious villain.
SonSon II plays differently from its predecessor. The stages are no longer horizontally scrolling and plays much akin to a more traditional platformer. In seven levels, Son Goku has to survive various jumping puzzles, fight off enemies with his staff and collect money in form of fruit.
Along the way, he can pick up various helpful items that can either be bought in stores or found hidden within the levels. They include: Medicine that refills Son Goku's health, a magic lamp that allows him to continue after losing a life, keys that open doors, a glove that breaks certain walls and a cloud that Son Goku can use to fly during boss-battles. Additionally, Son Goku can buy longer and more powerful staffs if he finds somebody who sells them.
- Hakkai (八戒) - A pig with a pitchfork. One of Sanzō's three companions.
- Sa Gojō (沙悟浄) - A kappa. One of Sanzō's three companions.
- Sanzō (三蔵) - A man travelling to retrieve Buddhist scriptures. Although he is helpless in defending himself, he finds three powerful disciples who aid and protect him on his journey to the West. The Ox-King captured him in the beginning of the game.
- The Immortal of Tiger Power (虎力大仙 Koriki Taisen) - The first boss.
- Red Boy (紅孩児 Kōgaiji) - The second boss, the son of the Ox-King and the Demonic Lady. Based on the Journey to the West character of the same name.
- "Goku" - The third boss, a fake Son Goku. Appears to be based on the Six Eared Macaque.
- The Immortal of Dragon Power (龍力大仙 Ryuriki Taisen) - The fourth boss.
- Ginkaku (銀角) - The first boss of stage 5, a demon that fights by throwing axes.
- Kinkaku (金角) - The last boss of the stage 5. Ginkaku's twin brother.
- Demonic Lady (羅剎女 Rasetsunyo) - The boss of stage 6, a woman with a giant iron fan called Bashosen. She is Ox-King's wife. Based on Princess Iron Fan.
- Ox-King (牛魔王 Gyūmaō) - The final boss.
Planner: Masaya Higashitani, Yoshiki Okamoto
Object Design: Susumu Ueda, Takashi Shouno
Scroll Design: Naoe Nonomura, Yuki Kyoutani, Yukiyo Kuramoto, Miki Mikami
Sound: Yoshihiro Sakaguchi, Manami Gotoh
Special Thanks: Akira Yasuda
Programmer: Masayuki Akahori, Yoshito Itoh
Presented by: NEC Avenue