
Monkey Ball is a 2001 platform and party video game created by Amusement Vision and released by Sega. The game was first introduced in Japan at the 2001 Amusement Operators Union trade show under the name Monkey Ball, as an arcade machine built on Sega's NAOMI platform and operated using a unique banana-shaped control stick.
The game features a story exclusive to the Japanese version. Here's a translated excerpt: AiAi, MeeMee, and Baby are a happy family living in peace on Jungle Island. One day, from the distant islands, GonGon, the leader of the Gorillas, launched a raid on the island, determined to claim all the bananas for himself! AiAi managed to escape the chaos and, exhausted, fell asleep. In his dream, the "Grand Monkey" revealed to AiAi the existence of a paradise known as "Banana Island" floating in the sky. To reach it, however, he must overcome a series of traps and obstacles. Fortunately, the Grand Monkey also taught AiAi a magical spell: "Ei Ei Poo!"—a powerful incantation that shields him from all danger. AiAi awakens quickly and, shouting "Ei Ei Poo!", a large ball descends from the sky. He jumps inside and soars high into the air. Now, it's time to survive the many dangers and reach Banana Island! If players complete the Master Stages (set above Banana Island) while controlling AiAi, MeeMee, or Baby, they can travel to Banana Island and enjoy all the bananas it has to offer. However, if playing as GonGon, he will be denied access to the banana-filled area while the other monkeys revel in their bounty.